The Real-World Impact of Epidemiological Models, with Adam Kucharski

The Real-World Impact of Epidemiological Models, with Adam Kucharski

Released Wednesday, 16th April 2025
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The Real-World Impact of Epidemiological Models, with Adam Kucharski

The Real-World Impact of Epidemiological Models, with Adam Kucharski

The Real-World Impact of Epidemiological Models, with Adam Kucharski

The Real-World Impact of Epidemiological Models, with Adam Kucharski

Wednesday, 16th April 2025
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0:00

Let me show you how to be a

0:02

good piece. Today I am honored to host

0:04

Adam Bucharski, a leaning expert in

0:06

infectious disease modeling, and epidemic

0:09

forecasting. Adam is a professor

0:11

of infectious disease epidemiology and

0:13

co-director of the Center for

0:16

Epidemic Preparedness and Response at

0:18

the London School of Hygiene

0:21

and Tropical Medicine. His research

0:23

focuses on harnessing data and

0:26

analysis to improve epidemic preparedness,

0:28

and he has contributed real-time

0:31

analysis to governments and health

0:33

agencies during major outbreaks, including

0:35

Ebola, Zika and COVID-19.

0:37

In this episode, Adam

0:40

takes us inside the

0:42

world of epidemiological modeling,

0:44

discussing how these methods

0:46

help refine predictions and

0:48

inform public health decisions.

0:50

We explore the challenges

0:52

of modeling infectious diseases.

0:54

from data uncertainty to

0:56

real-time forecasting, and the

0:58

importance of communicating findings

1:00

effectively to policymakers and

1:02

the public. Adam also

1:04

highlights common misconceptions about

1:06

epidemiological data and dies into

1:09

the world of automation and

1:11

AI in Epidemic Response. This

1:13

is an early invasion statistics,

1:16

episode 130, recorded November 26,

1:18

2024. Let me show you

1:20

how to be a good

1:22

Bayesian, change your predictions after

1:25

taking information. And if you're

1:27

thinking I'll be less than

1:29

amazing, let's adjust those expectations.

1:31

What's a Bayesian? It's someone

1:34

who cares about evidence. Welcome

1:36

to Learning Bayesian statistics, a

1:38

podcast about patient inference, the

1:40

methods, the projects, and the

1:43

people who make it possible.

1:45

I'm your host, Alex Andorra.

1:47

like the country for any

1:49

info about the show. LearnBatesat.com

1:52

is labless to be. Show

1:54

notes, becoming a corporate sponsor,

1:56

unlocking vision merge, supporting the

1:58

show on Patreon. is

2:01

in there. That's learn base stats.com.

2:03

If you're interested in one-on-one mentorship,

2:05

online courses, or statistical consulting, feel

2:08

free to reach out and book

2:10

a call at topmate.io/Alex underscore and

2:12

Dora. See you around, folks, and

2:15

best patient wishes to you all.

2:17

And if today's discussion sparked ideas

2:20

for your business, well, our team

2:22

at Poymce Labs can help bring

2:24

them to life. Check us out

2:27

at Pymce Dash Labs.com. Hello

2:30

my dear patients, hope you're doing

2:33

well. Two main announcements for today.

2:35

First and foremost, thank you so

2:37

much. to all of you who

2:40

sent testimonials about learning vision statistics

2:42

and intuitive base to support my

2:44

green card application. I was genuinely

2:47

touched, surprised, and moved by the

2:49

number, kindness, and generosity of messages.

2:51

I am so happy and grateful

2:54

to be surrounded by truly-minded, kind,

2:56

and helpful people. like you, I

2:58

received more than 40 testimonials. So

3:01

thank you so much to all

3:03

of you who've taken the time

3:06

out of their busy day to

3:08

work about a very nerdy endeavor

3:10

and how it changed the field

3:13

of statistics according to you. I

3:15

will of course let you know

3:17

what happens with my application and

3:20

I'm already planning a very special

3:22

in-person surprise for all of you

3:24

for February. 2026 but more info

3:27

will come in good time. So

3:29

again, thank you so much and

3:31

in the meantime, leave long and

3:34

prosper or shall we say leave

3:36

base and prosper and talking about

3:38

prospering if you are interested in

3:41

baseball and patient statistics and working

3:43

in an MLP team like let's

3:45

say the Miami Monins so that

3:48

would mean working with me if

3:50

you'd love that get to my

3:52

me get to meet me and

3:55

maybe working together in the baseball

3:57

research and baseball solutions teams. Well,

4:00

now is the time. Our teams

4:02

are growing fast and this is

4:04

your chance to get in on

4:07

something that's very special. Honestly, I

4:09

absolutely love what's going on there.

4:11

And we've just opened two brand

4:14

new roles, one baseball analyst for

4:16

the Solutions Group that's more here

4:18

to our junior applicants and a

4:21

senior one, which is senior data

4:23

scientist in the research group. It's

4:25

mine. So if you are passionate

4:28

about baseball research, I love working

4:30

on collaborative teams and well bonus

4:32

points, you know your way around

4:35

offense modeling approaches like for instance

4:37

patient methods with Pymc and Stan

4:39

and neural networks time series all

4:42

that stuff. Well we definitely want

4:44

to hear for you. I think

4:46

what we're doing in Miami is

4:49

some of the most exciting in

4:51

the MLB right now. Let me

4:54

know if you have any questions,

4:56

if you're a patron of the

4:58

show, you're on the discord with

5:01

me. Feel free to send you

5:03

any of your comments, questions, recommendations

5:05

of people. Send that to your

5:08

friends and maybe see you soon.

5:10

Miami. On that note, let's go

5:12

on with the show. Adam Kucherski.

5:15

Welcome to Learning Vision Statistics. Thank

5:17

you. Yeah, thank you for taking

5:19

the time and bearing with me

5:22

we've had a few technological problems

5:24

to record that episode folks that

5:26

was That was that was difficult,

5:29

but you know as they say

5:31

The obstacle is the way so

5:33

we are here And a big

5:36

thank you to Chris Wyman to

5:38

for putting us in in contact

5:41

Chris and I met at Stankon

5:43

2024 in Oxford. Chris was actually

5:45

in a panel discussion that recorded

5:48

with him. and Lisa Simonova, that

5:50

was episode 120 for people who

5:52

are curious and want to hear

5:55

more about how cool epidemiological science

5:57

and computational biology are. So feel

5:59

free to take that out. With

6:02

Adam today, we're actually going to

6:04

tackle some similar topics, but you

6:06

have a very wide and very

6:09

broad research. So that's why I'm.

6:11

I'm super happy to have you

6:13

on the show today. You do

6:16

so many things and you are

6:18

also a great science communicator. You've

6:20

written several books as I've said

6:23

in the introduction. So yeah, all

6:25

of these books will be in

6:27

the show notes. So people feel

6:30

free to check them out. I

6:32

definitely recommend them. They are absolutely

6:35

fascinating. But before we touch on

6:37

the end, can you tell us

6:39

with your tree? Actually nowadays, Adam

6:42

and how you ended up working

6:44

on this. Yeah, sure. So, I

6:46

mean, my work kind of bridges

6:49

really understanding epidemics and getting better

6:51

at predicting and responding to them.

6:53

So there's a mix of aspects

6:56

to that. So some of it

6:58

is understanding the drivers of what

7:00

we see in terms of how

7:03

things spread. So for something like

7:05

thank you fever, that might be

7:07

climate influences, accumulation of immunity in

7:10

the population for something like, say

7:12

flu or COVID. the implications of

7:14

vaccination over time, how those viruses

7:17

evolve. Alongside that we're also doing

7:19

a lot of work to build

7:21

up the methods and tools that

7:24

we need to respond to very

7:26

quickly during COVID. A lot of

7:29

these things were developed very quickly,

7:31

often just working over weekends and

7:33

can we actually do a lot

7:36

better particularly for the predictable questions

7:38

that we know we're going to

7:40

have to answer. In terms of

7:43

how I got into it, my

7:45

backgrounds originally in maths, have applied

7:47

maths as my PhD. But even

7:50

that was starting to go more

7:52

in this direction of epidemiology and

7:54

questions around. how we can understand

7:57

the process of infectious disease. And

7:59

for me, as a field, it

8:01

kind of sits quite nicely between

8:04

something where having some mathematical and

8:06

statistical understanding can give you a

8:08

lot of value very quickly. But

8:11

also, there's enough unknowns about the

8:13

underlying rules and processes. It's not

8:16

some like physics where we have

8:18

a lot more mechanistic understanding. So

8:20

it means. sort of squeezing a

8:23

lot more out of the data

8:25

you have available, particularly under pressure

8:27

in a situation like an epidemic.

8:30

I see, okay, that's very interesting.

8:32

So it's something that, yeah, was

8:34

a long time coming, right? You've

8:37

always kind of been interested in

8:39

these topics, at least since your

8:41

past high school studies, right? Yeah,

8:44

I think there's a lot of

8:46

those questions where, yeah, obviously has

8:48

an enormous impact on people, but

8:51

also just from a kind of

8:53

curiosity point of view, these are

8:55

quite hard questions and often the

8:58

methods that are in the textbooks

9:00

don't quite work for what you

9:02

need to do. So it's an

9:05

ongoing interesting research area to be

9:07

in because almost every epidemic you

9:09

work in, what you thought you

9:11

knew and what you thought you

9:13

had solved. Suddenly you happen. And

9:15

so yeah, it's kept me busy

9:17

and kept me interested along with

9:20

many of my colleagues. Yeah. And

9:22

what about patient stance? Do you

9:24

remember when you were first introduced

9:26

to them? So I think it's

9:28

particularly doing PhD. So I think

9:30

my kind of undergrad is a

9:32

lot more traditional math. So it's

9:34

a relatively little statistics, a lot

9:36

more kind of theory. to the

9:38

sort of thing where you'd learn

9:40

measure theory rather than learning the

9:42

kind of coming at it from

9:44

a data point of view. I

9:46

think during my PhD, I started

9:49

working a lot more with data,

9:51

and especially if you start to

9:53

look at processes involved in diseases

9:55

versus involving immunity, then that's the

9:57

next question is, well, how could

9:59

we estimate things meaning? meaningfully within

10:01

that. And then particularly if you

10:03

have patchy bits of data or different

10:05

studies that you want to combine in

10:08

some way or if you have some

10:10

analysis you've put together and then you

10:12

want to make statements about additional

10:15

data coming in, basic statistics are

10:17

a natural framework for doing that.

10:19

And so really in the mix

10:21

of my work in some cases

10:23

you just get simple probability problems

10:25

and base formulas are nice. get

10:27

out of jail way of solving

10:30

that problem. And in other cases,

10:32

it's more of a framework for

10:34

thinking about the entire analysis that,

10:36

you know, you want to be able

10:38

to come to the best possible explanation

10:40

or the best possible evidence at

10:42

even point in time, but then you

10:45

want to update that as you get

10:47

more data coming in and again it

10:49

gives you a very nice toolkit for

10:51

doing that. Yeah, yeah. Yeah, that makes

10:53

sense. Damn. That's very fussy to

10:55

you here. brings me a lot

10:57

of more questions for you

10:59

Anna. Yes, one of these

11:01

questions that I have for

11:04

you is, especially during COVID,

11:06

Bayesian modeling became a crucial tool.

11:08

I remember I did some work

11:11

at my very low level at

11:13

that time, but you did a

11:15

bunch of work on that and

11:18

as you were saying, I mentioned

11:20

there were a lot of very

11:23

short nights and very long weeks.

11:25

Can you share specific examples of

11:27

how these models were able to

11:29

inform public health decisions? Yes,

11:31

I think there's quite a

11:34

few instances, particularly around scenarios

11:36

where models can be a

11:38

very useful kind of decision

11:40

support tool. Because essentially if you're

11:42

going to make a decision about

11:44

what to do in an epidemic,

11:47

everyone has a model in their

11:49

head because if you think let's do

11:51

this, let's try this. you're making some assumptions

11:53

about what you think is going to happen,

11:55

you make some assumptions about how you think

11:57

epidemics work. So models are a very nice way

11:59

of it. allowing us to really write down

12:01

and formalize what we think those processes

12:04

are and what we think the

12:06

interventions are going to do. And then

12:08

we can debate whether that's reasonable,

12:10

whether that's not, so we can see

12:12

if that generates any counterintuitive effects.

12:15

But in doing that, you really want to

12:17

capture the extent of information you have

12:19

about what you're dealing with. So even,

12:21

for example, the question of how much

12:23

effort is it going to take to

12:25

get transmission down? One of the key

12:28

things that is going to influence that

12:30

is how much transmission there really is.

12:32

So a lot of the analysis that we did,

12:34

being able to pass around uncertainty is

12:36

really important. So very early in

12:38

the pandemic, for instance, because we

12:40

were relying on quite uncertainty from

12:43

China, quite uncertain data about

12:45

exported cases, we had some sense

12:47

of what transmission would do in

12:49

a country without any control measures,

12:51

but there was quite a large

12:53

amount of uncertainty on that probably

12:55

reproduction number. somewhere between two and

12:58

four. And so what we wanted to do

13:00

is when we generate UK scenarios to

13:02

present them, we didn't want to

13:04

give one number, we wanted to

13:06

say, look, we don't know actually it's more

13:08

the upper end or lower end of this,

13:11

but we want to kind of define

13:13

that uncertainty in what we simulates.

13:15

And then after that wave comes through, you

13:17

know, we had a lockdown as like many

13:19

other countries, there was this push to

13:21

reopen and then the question is okay, so

13:24

we give we have that wave. what's

13:26

the reopening going to look like? And

13:28

again, that's where these kind of basic

13:30

methods we have very helpful, because

13:32

we can take the uncertainty and

13:35

perhaps we've got more confidence now

13:37

about what we're dealing with, but then

13:39

we want to pass that level of

13:41

confidence into what's going on in the

13:43

future. And then, you know, it's very

13:45

inside emerging, that became even more important

13:47

because often the alpha we would

13:49

have some degree of confidence about

13:51

how much more transmissible it was,

13:53

And in any analysis, for

13:56

example, we did a lot of

13:58

work early in 2021, how... quickly you're

14:00

going to have to vaccinate. And I

14:02

think there's a lot of pressure to

14:04

lift lockdown and try to understand that

14:07

trade-up. If you're vaccinating at this rate

14:09

and you're lifting lockdown this quickly, what's

14:11

that going to look like? And again, none

14:13

of those values you had very precisely and

14:15

you had more epidemic data coming in

14:17

all the time. And as particularly that

14:20

process of reopening in 2021, there's a

14:22

very tight relationship between models and policy

14:24

because in the UK more of the few

14:26

times where the policy was actually very informed

14:29

by what was useful from a technical point

14:31

of view. So what they did was they

14:33

had these series of steps in the road

14:35

madness. It was designed to give enough signal

14:38

in the data post each step that

14:40

if something was going very wrong, they

14:42

wouldn't have implemented another step before

14:44

you had that signal. So they

14:46

would have deliberately spaced out so

14:49

the models and the epidemiologist would

14:51

have enough time to work out what that

14:53

relaxation had done. So again, from a

14:55

basic important... point of view that

14:57

that's really nice because it gives

14:59

you enough time to kind of

15:02

update your posterior sensibly before you

15:04

do the next step and work out

15:06

what effect that's going to have. Right, yeah,

15:08

yeah, yeah, yeah, okay, that's, that's, I

15:10

didn't know, I didn't know there

15:12

was that level of coordination where

15:14

you could actually do that, you know, go

15:16

there. There were many examples where,

15:19

yeah, it didn't, it didn't work

15:21

in such a coordinated fashion, but

15:23

I think that was that that

15:25

roadmap reopening is one where there

15:27

was a much tighter relationship

15:29

between the questions come

15:31

down from policy and what you

15:34

know models needed to say something

15:36

sensible about the

15:38

implications. Yeah, yeah, and I guess, I mean,

15:41

I was so wondering, you know, how

15:43

much do you think the pendulum

15:45

has swung back from from then,

15:47

you know, like do you think will

15:50

be faster to implement

15:52

these workflows and improve them

15:54

next time there is a

15:57

pandemic? Or will we have

15:59

to? work from a blank slate

16:01

because politics is so short-sighted

16:04

with very short, you know,

16:06

cycles? Yeah, I think that's

16:08

a really good question. I

16:10

think there's some things that

16:12

have been positive in terms

16:15

of progress, so I think in

16:17

some people we're doing others in

16:19

consolidating a lot of the tools

16:21

that are available. So some things

16:23

now that we, you know, look

16:25

at quick questions that

16:28

age 5 anyone. Questions that

16:30

I just wouldn't have bothered doing

16:32

previously just as a curiosity because

16:34

it would have been three four

16:36

hours just for maybe question

16:38

and now in 20 minutes you can

16:40

get a rough example. So I think

16:42

that's quite nice is bringing things into

16:44

reach. But I think in terms of

16:46

just staff capacity and people to do this

16:48

work, I think there are a lot of people

16:51

who put a huge amount of time in

16:53

often as around the world getting pulled

16:55

off different roles and off other projects. And

16:57

so I think in a way in that

17:00

sense, we probably don't have

17:02

the same workforce who could undergo that

17:04

in our pressure for that a matter

17:06

of time. So in a way that

17:08

creates a necessity, we need to get

17:10

better tools because we don't have, I

17:12

think that volume of people, but

17:15

also just all our projects, we

17:17

basically took people off a lot

17:19

of other funded projects, and

17:21

I think we wouldn't have the results

17:23

to do that in the same way.

17:25

Now, so for me, I think particularly

17:27

what we're interested in the moment is

17:29

if you imagine the set of tasks you might

17:31

have to do in an epidemic. Some are tasks

17:34

that a lot of other people have to

17:36

do, and we can really predict ahead of

17:38

time you're going to need to do that.

17:40

So stuff like working out the severity of

17:42

infection or working out the transmission. We know

17:45

we're going to need that done. We know lots

17:47

of people who are going to do that.

17:49

So that's a really good task for automation

17:51

and getting really leadingage, basic

17:53

methods. standardized if people can ever want

17:55

to do that and we don't all have to

17:57

duplicate effort. There's other things that would be really

17:59

specific. Maybe within a country there's a

18:02

kind of subgroup that's particularly important

18:04

or there's a certain variance or

18:06

something you might want to deal

18:08

with and that's going to require

18:10

more domain knowledge. And I think

18:12

at the moment, even if you

18:14

talk to people at different outbreak

18:16

organizations around the world, they probably

18:19

spend six or 70% of their

18:21

time on quite low level, predictable

18:23

data ranking type questions rather than

18:25

30% of expertise led to questions

18:27

they'd want. I don't necessarily think

18:29

in a pandemic people they're not

18:31

working less hard because everyone wants

18:33

to contribute as much as they

18:35

can, but I think what I'd

18:38

like to see is a lot

18:40

more time on that 30% and

18:42

going much deeper into what we

18:44

can understand, rather than spending a

18:46

lot of time, you know, even

18:48

just trying to get ahead the

18:50

sense of the data and the

18:52

basic tasks to answer very simple

18:55

questions. Not sure I'm

18:57

really reassured by that answer, but

18:59

yeah, that's absolutely realistic, the realistic

19:01

answer. Some things I'm also really

19:03

curious about as a, because I

19:05

see that a lot as a

19:08

modeler myself, is where the, you

19:10

know, the common misconceptions that you've

19:12

seen the public or elected officials

19:14

or even professionals have about epidemiological

19:16

data in what the scientific community

19:18

can do to clarify these misunderstandings.

19:20

Yeah, I think that's a really

19:23

good question. I mean, I think

19:25

one common misconception is even just

19:27

what data are as a thing.

19:29

You know, I think often when

19:31

people talk about law data, they're

19:33

talking about inferred estimates. So I

19:36

think one example of this is

19:38

excess stats, that I think the

19:40

media... often treat as a measured

19:42

thing rather than actually a counterfactual.

19:44

And I think I remember talking

19:46

to journalists about the comparison with

19:49

food. I think a lot of

19:51

them discovered that the flu mortality

19:53

statistics they've used every year actually

19:55

involved some quite big modeling assumptions

19:57

about seasonal patterns behind them. And

19:59

there isn't just this magic number

20:01

that we measure. Right. I think

20:04

similarly with a lot of the

20:06

estimates, for example, in the UK

20:08

they ran randomized testing surveys surveys.

20:10

randomly tested people in the community

20:12

and reported it. And that number

20:14

that wasn't a raw proportion because

20:17

of course you needed to do

20:19

some standardization across groups and waiting

20:21

and in some cases because it

20:23

was it was quite noisy across

20:25

multiple panels they would have you

20:27

know a kind of smooth underlying

20:30

proportion and then in further. So

20:32

it was sensible modeling but there

20:34

was modeling behind that and I

20:36

think the misconception often is that

20:38

these things award data, but often,

20:40

yeah, even a very simple thing

20:42

if you calculate, if you run

20:45

a survey and calculate a proportion,

20:47

you're making some modeling assumptions, or

20:49

if you know, are we going

20:51

to adjust for age, why are

20:53

you adjusting page, why are you

20:55

not adjusting to something else, you're

20:58

making assumptions about what you think

21:00

are important drivers of that thing

21:02

you're measuring. So I think that's

21:04

probably one thing we can get

21:06

better of communicating is that actually

21:08

model estimates. And actually a lot

21:10

of the things that sometimes people

21:13

treat as super complex models are

21:15

actually just quite straight simple steps

21:17

for thinking about data. So even

21:19

one of, you know, if you've

21:21

got a bunch of hospitalizations over

21:23

time and you want to know

21:26

when the infections happened, you can

21:28

use quite simple like a decomposition

21:30

model just to take that and

21:32

work out when the infections are.

21:34

And I think often in public

21:36

perception when people talk about models,

21:39

what they mean is very complicated.

21:41

scenario models that people are assuming

21:43

are used to make forecasts. I

21:45

think it's often a kind of

21:47

a crystal ball of uses big

21:49

complex models to say what's going

21:51

to happen. And I think in

21:54

reality what happens is that often

21:56

the more complex models are used

21:58

for scenarios and like what if

22:00

because we can't we can't make

22:02

forecasts often in pandemics as well

22:04

because you'll be forecasting what policy

22:07

makers are going to do. And

22:09

if your models are used as

22:11

tools to support their decisions, it

22:13

becomes quite odd to use that

22:15

as a forecast. I mean, I

22:17

think the example I sometimes get

22:20

is like, yeah. And at the

22:22

point in time you want to

22:24

understand the implications of your decisions.

22:26

What you don't really want is

22:28

someone on your shoulder saying, I

22:30

bet you're going to fold later

22:32

this round. What you want is

22:35

someone who can say, look, this

22:37

is likely, this is likely the

22:39

situation you're going to face, this

22:41

is the risk you're taking on,

22:43

if you fold, this is potentially

22:45

what the outcomes are going to

22:48

be. So that's really how a

22:50

lot of these models are used

22:52

in kind of decision support. But

22:54

I think in public consciousnessness, they're

22:56

often, this is going to happen.

22:58

in the future. And I think

23:00

part of it is communication and

23:03

particularly I think getting people to

23:05

be able to play with the

23:07

simple models can be very helpful.

23:09

So they realize it's not this

23:11

super complex thing. It's probably what

23:13

they're doing in their head, but

23:16

just writing it down in a

23:18

bit more restructured way. Yeah, yeah.

23:20

I find also indeed, you know,

23:22

walking through scenarios is something that's

23:24

really helpful to people. because, well,

23:26

they can imagine the scenarios and

23:29

that's much more, you know, tangible

23:31

and concrete than numbers and posterior

23:33

distributions. I can see that all.

23:35

I mean, sports is a lot

23:37

like that, especially baseball, lots of

23:39

different discrete scenarios. Yeah, and I

23:41

think, you know, often people, particularly

23:44

epidemics, are kind of doing it

23:46

in their head all in the

23:48

time that, you know, The epidemic's

23:50

going off because it's going to

23:52

be a problem. and then you

23:54

get a few data points that

23:57

seem to be tailing off a

23:59

bit. And basically everyone's doing that

24:01

updating in their head of where

24:03

they think it's going. But they

24:05

often, I would have loved to

24:07

have seen more politicians and journalists

24:09

actually write down their, yeah, you

24:12

could get them to actually just

24:14

write down their prediction and their

24:16

kind of distribution of what they

24:18

think is going to happen and

24:20

then see how there's update and

24:22

then you could actually. give

24:25

them a better understanding of what's

24:27

going on in their head relative

24:29

to actually what's possible given the

24:32

data was coming in. Yeah, yeah,

24:34

but So I completely agree with

24:36

that and I really love that

24:38

But I think here the incentives

24:40

are really bad for politicians might

24:42

be is then if you like

24:44

if you publicly and privately I

24:47

think I think yeah, I think

24:49

that's I think that's really that's

24:51

I think that's a really good

24:53

point. Yeah, I think getting politicians

24:55

to write that what it's going

24:57

to have in public is very

24:59

difficult. But I think even privately,

25:01

I think there were a lot

25:04

of people probably not doing that

25:06

that would. Yeah, so I, yeah,

25:08

I mean, amongst colleagues and stuff,

25:10

we sometimes just had, just probably

25:12

more things, when you think this

25:14

study comes out, what do you

25:16

think is going to show? And

25:19

I think it's sometimes quite, we

25:21

like to kid ourselves. So even

25:23

if it's just writing. I'm like

25:25

completely on board in helping people

25:27

develop a more probabilistic thinking. You

25:29

know, I think you doing the

25:31

work you're doing and also the

25:34

communication work you're doing is very

25:36

important. All your books, that's also

25:38

why I have these podcasts, people

25:40

like Nate Silver. and writing books

25:42

is very important too. I don't

25:44

know if you read his last

25:46

book on the edge, but that's

25:49

very important too for that, right?

25:51

And I think that'd be awesome

25:53

if we were gearing towards that

25:55

direction. But yeah, the problem is

25:57

like the incentives in. The public

25:59

incentives and politics are so bad

26:01

when it comes to that that

26:04

you actually have a much better

26:06

Standing if you just you know

26:08

say Anything and and everything and

26:10

just are not held accountable for

26:12

that then actually You know betting

26:14

on something that would happen and

26:16

then and then changing course if

26:19

actually what you said would happen

26:21

did not and then you know

26:23

I think partly from the communication,

26:25

there's also the, yeah, what are

26:27

the things that we can do

26:29

meaningfully and what are the things

26:31

that you can encourage people to

26:34

do versus just want to be

26:36

feasible. And I think also just

26:38

from a modeling point of view,

26:40

yeah, sometimes there's this idea that

26:42

for political decisions, you know, you

26:44

should have this big model with

26:46

absolutely everything in and all the

26:49

kind of the weights of how

26:51

you do everything. And I can't

26:53

see any political party wanting to

26:55

do it because ultimately those things

26:57

are going to be weighed, not.

26:59

in a kind of written down,

27:01

you know, we're going to put

27:04

10% on this and 15% on

27:06

this. And so I think it's

27:08

working out, yeah, where the science

27:10

can be really informative and where

27:12

actually there's more of that kind

27:14

of human political element and that,

27:16

you know, that's not the best

27:19

battle to be through fighting at

27:21

this point. Yeah, yeah, yeah, it's

27:23

a great point. And actually in

27:25

your... Talking about your books in

27:27

the rules of contagion, you explore

27:29

why things spread. And I really

27:31

love that. So can you tell

27:34

us a bit more about that?

27:36

And how does patient thinking help

27:38

in understanding these patterns, especially for

27:40

diseases? Yeah. So I think that's,

27:42

um, striking what in the book

27:44

is a set out. thinking that

27:46

there would be these analogies in

27:48

other fields and I wasn't sure

27:51

necessarily how strong there would be.

27:53

But the more I dug into

27:55

that, I mean, there's actually... there

27:57

were in many cases very explicit

27:59

and very generally informative. For example,

28:01

after the 2008 financial crisis, there

28:03

was a very purely described epidemic

28:06

thinking that drove a lot of

28:08

the interventions resource, things like ring

28:10

fencing, things like capital requirements of

28:12

banks that were risk in network.

28:14

It's really about thinking about it

28:16

like a contagion problem. Similarly, if

28:18

you dig into the history of

28:21

companies like Buzzfeed that were very

28:23

good at generating viral content. They

28:25

were actually writing research reports on

28:27

how you evaluate the reproduction number

28:29

of marketing campaigns. And actually, that's

28:31

what we discovered, that Buzzfeed journalists

28:33

would have a measure equivalent to

28:36

the reproduction number as a metric

28:38

for their articles. So it wasn't

28:40

just this quite fuzzy comparison. Actually,

28:42

this was the same bits of

28:44

theory. that were appearing between these

28:46

two fields. I think one thing

28:48

I find quite interesting on the

28:51

Bayesian angle in how things spread

28:53

is particularly some of the debates

28:55

around how you convince people and

28:57

how people adopt beliefs and they

28:59

take off. Because there was quite

29:01

a popular idea for a while

29:03

known as the backfire effect, which

29:06

is where if you try and

29:08

convince someone, you can end up

29:10

basically just strengthening their existing belief.

29:12

and this idea that attempts to

29:14

change people's beliefs can kind of

29:16

backfire, which also doesn't bode well

29:18

for any kind of social progress

29:21

because it's this idea if you

29:23

try and convince someone that marriage

29:25

equality or something is a good

29:27

idea, it's just going to need

29:29

them to be entrenched. But what

29:31

subsequently happened is a lot of

29:33

the work, both on the applied

29:36

side of actually people kind of

29:38

get these, get support for these

29:40

kind of, this progress. but also

29:42

on some of the scientific side

29:44

of people studying them, suggested it's

29:46

actually much closer to a Bayesian

29:48

problem, that it's not that you're

29:51

leaving people. to entrench their beliefs.

29:53

Rather, if you give people weak

29:55

evidence, you're not going to shift

29:57

their distribution much. I thought it

29:59

was kind of really interesting. And

30:01

I hadn't actually thought about it

30:03

quite much in that way. And

30:06

it kind of makes sense that

30:08

even if you've got like a

30:10

quite strong prior for something, if

30:12

someone gives you evidence that agrees

30:14

with that prior. it's going to

30:16

look pretty similar after us, and

30:18

especially because we're not doing all

30:21

those calculations in our head. We're

30:23

just sort of seeing the feeling

30:25

we've come away with. And it

30:27

really struck me that actually in

30:29

those situations, we're probably much better

30:31

evaluating the effects of evidence that

30:33

we disagree with, because the posterior,

30:36

you know, just mathematically expected the

30:38

posterior to move more. And so

30:40

perhaps the situations where what people

30:42

were thinking was about flash effects,

30:44

it's more just we're better. critiquing

30:46

evidence we disagree with rather than

30:48

the ones that kind of line

30:50

up because if it agrees with

30:53

us we're going to walk away

30:55

the same opinion afterwards anyway. So

30:57

yeah I think that was it's

30:59

obviously a much harder problem to

31:01

study in terms of spread of

31:03

relief and there's so many factors

31:05

that can play into that but

31:08

yeah there's still a lot of

31:10

ongoing debate on the extent to

31:12

which people's adoption of beliefs and

31:14

behaviors, these Bayesian versus you know

31:16

some other factors that kind of

31:18

explain how those are updated over

31:20

time. Yeah, I see. That's, that's

31:23

really amazing. I love that. I

31:25

didn't know that, that example about,

31:27

what's the, what's the, what's the

31:29

website you were saying? Ah, well,

31:31

Bosfield, yeah, yes, thank you. I

31:33

was, it's remarkable, yeah, and it's,

31:35

it was coming to it because

31:38

they did, you know, campaigns about

31:40

a hurricane Katrina with. I mean,

31:42

none of these were viral and

31:44

this one they keep findings that

31:46

this wasn't like COVID where it

31:48

just spends, spends, spends, but you

31:50

know, for 10 shares they might

31:53

get an extra seven or eight.

31:55

So, you know, if you get

31:57

it, if you spark lots of

31:59

little clusters of sharing, you might

32:01

actually. yet quite quite considerable additional

32:03

uptake as a result. I think

32:05

there was one that was a

32:08

marketing campaign for detergent and it

32:10

wasn't accountable at all basically. So

32:12

there was quite a nice quantifying

32:14

that there's certain things that people

32:16

obviously want to tell people about

32:18

and others that even if you

32:20

got the biggest marketing budget in

32:23

the world you're going to struggle

32:25

to make washing up liquid contagious.

32:28

You know, I'm something I'm I'm curious

32:30

about and I asked this question to

32:32

Chris to at Stankon is Confrictly what

32:35

does it look like for you to

32:37

work on an epidemiological model? Like

32:39

who are you talking to and what's

32:42

your workflow and technical stack? Yeah, that's

32:44

really good question. Generally, anything we build

32:46

starts with the problem and often that

32:49

problem either comes from someone, if

32:51

there's a policy where a question comes

32:53

from, so on policy sites, so maybe

32:55

it's scientific advisors to certain agencies in

32:58

the case of like an applied organization

33:00

at MSF or WHO, it will

33:02

come from a representative who we're working

33:04

on maybe that outbreak. or that situation.

33:07

And there'll often be quite specific things

33:09

that people are interested. Yes, it

33:11

might be a forecast of actually that.

33:13

What are we dealing with? It might

33:16

be that there's a plan to implement

33:18

vaccination or control measure. A lot of

33:20

the work within the BOLA, for

33:22

example, different control measures being proposed and

33:25

people wanted some idea of the relative

33:27

impact that that would have. There's also,

33:29

of course, just on the scientific side,

33:32

so the work we've done. round

33:34

effects of behavioral immunity, it might be

33:36

that you've got lab colleagues who've noticed

33:38

some interesting features and want to work

33:41

out. How can I get sufficient

33:43

estimates out of my data? I mean,

33:45

I mean, this is, I think another

33:47

example where Bayesian thinking is very helpful

33:50

that you might have say lots and

33:52

lots of antibody responses. And you

33:54

don't want to analyze them all as

33:56

like individual data sets because there's going

33:59

to be some commonalities in just how

34:01

the biology works between individuals. So having

34:03

this kind of hierarchical models can

34:05

be very powerful because you can have

34:08

shared information just on the underlying dynamics

34:10

across the population, but you can also

34:12

have individual features of what we

34:14

look at previously and this sort of

34:17

thing. the kind of model was that

34:19

it depends a bit on whether it's

34:21

similar to another problem you've seen. So

34:24

a case of policy question, often

34:26

what we'll do is, you know, in

34:28

the many, many models and things we've

34:30

dealt with previously, you'll find the thing

34:33

that's most similar. And I think increasingly

34:35

we're seeing progress in libraries. So

34:37

a lot of the work we do

34:39

in is in our or in some

34:42

cases you can kind of stand back

34:44

ends. And so you'll take something

34:46

that maybe is from the library that

34:48

you think is most appropriate for that

34:51

and then a model that's templated up

34:53

that's closest to that. And then ideally

34:55

you'll just plug in and work

34:57

straight away. Often you might either adapt

35:00

some features of the model process in

35:02

terms of say how transmissions happen or

35:04

what groups are affected or you

35:07

might bring in different data. You might

35:09

have a model set up for UK

35:11

contact structure and you'll just import data

35:14

from somewhere else so you can adapt

35:16

it. In other cases, you might

35:18

get something that's a very specific, quite

35:20

neat question. So, you know, for example,

35:23

I don't know, like the ones doing

35:25

COVID, testing people at certain types of

35:27

gathering or something, and that's not

35:29

something necessarily you have a model off

35:32

the shelf, but in some cases, the

35:34

equation is quite simple to write down.

35:36

You know, if you've got this

35:38

many people and you're testing this many

35:41

at this point in time, and in

35:43

that case, we might just build something

35:45

more to smoke. The challenge always, I

35:48

mean like with any kind of

35:50

software development problem, is to what extent

35:52

do you do something quick for a

35:54

very specific problem versus take on coding

35:57

debt if you've got to do that

35:59

problem repeatedly. And so I think

36:01

we're getting a better sense now. There's

36:03

certain things that are sufficiently complex. There's

36:06

large enough script for bugs. It's going

36:08

to be useful for enough people.

36:10

Well, actually, that makes sense to package

36:12

up more consistent library. And there's other

36:15

things that actually are simpler enough and

36:17

transparent enough and kind of bespoke enough

36:19

that you don't want to build

36:21

a software tool for every single one

36:24

of those. Some of those you can

36:26

just do quickly as the problem arises.

36:28

Yeah. Yeah. That makes tons of sense.

36:31

And once you're, I'm wondering also

36:33

the size of the of the teams

36:35

in these, in these cases, because obviously

36:37

each time I talk to a, to

36:40

a modeler in your field, it

36:42

sounds like the models are really big

36:44

and huge and and take a lot

36:46

of time to work on because they

36:49

are so complex. So yeah, I'm wondering

36:51

how many people does it take

36:53

to work on a model and how

36:55

do you actually do that? Because Like

36:58

yeah, is everybody working on the model

37:00

at the same time? Do you have

37:02

some team for that part of

37:04

the model, another team for the other

37:07

part? How does that? Yeah, so I

37:09

think, I mean, to give you an

37:11

example of some of the big

37:13

kerbic scenario models that are used by

37:16

our group in the UK, I haven't

37:18

got the get have worked on it.

37:20

It's probably, you know, at least 10,

37:23

50 people who made it's a

37:25

central contributions to that co-based at their

37:27

various points in time. And in time.

37:30

And in some case, can be, I

37:32

mean, ideally we'd make these things as

37:34

module as possible. So early on,

37:36

for instance, I had some colleagues who

37:39

have focusing very much on the transmission

37:41

dynamics and kind of how people interact,

37:43

what interventions were going to be,

37:45

and I worked a lot more on

37:48

the sort of disease burden module. So

37:50

once you have transmission infections, you can

37:52

convert those infections, the investment of how

37:55

many are you going to be

37:57

hospitalized for. So then you have that

37:59

kind of basic model structure, but then

38:01

over time that got... expanded because variance

38:04

came. in, vaccines came in, and

38:06

you ended up with multiple versions of

38:08

those models. And there's always this kind

38:10

of challenge of, you know, do you

38:13

make kind of one core model that

38:15

has sufficient flexibility to do all

38:17

those problems? Or do you kind of

38:19

fork a model and use it for

38:22

a special case? And you're not going

38:24

to use it again. So that model

38:26

has actually been used for multiple

38:28

countries. We adapted it to a whole

38:31

range of different settings, I think. patterns

38:33

of immunity and infection. And in that

38:35

case, it didn't make sense just

38:37

to build that into the original model

38:40

because it was just such a kind

38:42

of specific example. But I think that's

38:44

one thing where as well, if we

38:47

had to go back now, because

38:49

there's so many versions of the model

38:51

and so many applications because it's real

38:53

time we had to deliver that very

38:56

quickly, it's obviously harder to now say

38:58

how we would do that for

39:00

flu epidemic. And so I think what

39:02

we're trying to move more towards is

39:05

these very modular examples that you can

39:07

plug in all the bits you

39:09

need but also have that capacity to

39:11

adapt it and I think that's just

39:14

that's that's kind of an ongoing challenge

39:16

that you can have these things that

39:18

very stable and structured but very

39:20

hard to adapt or you can have

39:23

these things that very maybe flexible and

39:25

easy to adapt but not necessarily as

39:27

kind of efficiently structured as you like.

39:30

I mean there are examples as

39:32

well modeling where it might be one

39:34

or two people developing something quite quickly

39:36

or just making use of a library.

39:39

I mean some of the popular

39:41

methods for example for estimating reproduction numbers

39:43

that tool will have been used by

39:45

a huge amount of people but obviously

39:48

the active contributors to the development might

39:50

be a lot smaller. Okay, yeah

39:52

I see. Yeah so a big big

39:55

diversity in the in the size of

39:57

the other projects. And do you have

39:59

a... Do you have a favorite type

40:02

of models actually that you'd like

40:04

to share with this? So I think

40:06

one of, well I think one of

40:08

the models that I think has delivered

40:11

a lot of value in various

40:13

things that we've worked on over the

40:15

years is actually both on some of

40:17

the H7 and 9 analysis we did

40:20

about 10 years ago for the efforts

40:22

in China where you had infections

40:24

coming from poultry and potential human transmission

40:26

as well. There's a big question of

40:29

looking at that human data, how much

40:31

was coming for human human infections. And

40:33

we actually fat. you've got an

40:35

analogous version of the problem with some

40:38

of the COVID variants. So for Delta,

40:40

how much of this was imported cases

40:42

from India versus transmission establishing in

40:44

countries. And in both those situations, so

40:47

first of all, it's a bit of

40:49

a modeling headache because a lot of

40:51

traditional models are structured in a way

40:54

that basically says if you've got

40:56

your cases over time. the new cases

40:58

that appear have to have been one

41:00

of those past ones that infected them.

41:03

So if you look at a

41:05

lot of the common calculations for how

41:07

you do reproduction numbers, it's known as

41:09

a generative model. So in other words,

41:12

when your equation is the kind of

41:14

specific version. So the new infections

41:16

are the products of the infections that

41:18

come before. Someone has caused that infection.

41:21

If you've got importations or spillover, that's

41:23

no longer the case. You've actually got

41:25

this additional term coming into your

41:27

equation. So it makes it a trickier

41:30

inference problem if you've got two groups

41:32

just to infecting someone. But it can

41:34

also be more powerful because in

41:36

the case of avian flu we knew

41:39

when the wild like poultry markets were

41:41

closed and in the case of Delta

41:43

we knew when the travel ban against

41:46

India was implemented. So what you've

41:48

got as a kind of estimation problem

41:50

you've got two things that influence your

41:52

infections but you know the kind of

41:55

shape of one of these, because you

41:57

know when the market goes, you

41:59

know when the flight buttons came in.

42:01

And suddenly that gives you a lot

42:04

more estimation power on the thing you

42:06

care about, which is humans' human

42:08

transmission. So I think for me that

42:10

that's just a really nice example of

42:13

a model that it's not super common.

42:15

It's very relatively easy to explain. It's

42:17

like there's two things that can

42:20

affect someone which is it. But actually,

42:22

you can squeeze a remarkable amount out

42:24

of your data as soon as you

42:27

know the shape of one of those

42:29

processes. Okay. And does that... I

42:31

mean, it obviously comes with significant challenges.

42:33

I'm using these models. detail of these

42:36

changes that you face when creating such

42:38

models? Yeah, I think there's a

42:40

whole mix. I mean, in some cases,

42:42

there's, you know, just just understanding the

42:45

person you define a model that for

42:47

a lot of outbreaks, there's a lot

42:49

of things you'd like to know

42:51

the role of in in a process.

42:54

So for example, how different age groups

42:56

are interacting or affected by certain things,

42:58

but in some cases you might not

43:01

have the data that you need

43:03

to actually pick that apart. So a

43:05

good example in COVID was a lot

43:07

of people, you know, the epidemic would

43:10

come down, a lot of people

43:12

would argue about why that was. And

43:14

actually if you just look at case

43:16

data or just look at deaths, it

43:19

could be immunity, it could be changing

43:21

in behavior. it could be something

43:23

to do with the climate, it could

43:25

be, you know, a whole range of

43:28

different things that could influence that transmission

43:30

and just looking at one time series

43:32

of animals, you can't distinguish what

43:34

those are. You really need some data

43:37

on antibiotics, you need some data on

43:39

social mixing to tell you which of

43:41

those is the most likely explanations.

43:43

I think that's often a big challenge

43:46

is where you have lots of potential

43:48

explanations and you can't actually untangle them.

43:50

I mean the other... to use H5N1

43:53

as a current example, unlike the...

43:55

H5N9 and Delta where we knew how

43:57

that shape of the introductions was changing.

43:59

We don't know that for H5. So

44:02

now you get cases popping up

44:04

and they say they haven't had a

44:06

contact with poetry, maybe it's a wild

44:08

word, maybe it's a human, we've got

44:11

no idea. And I think that's that's

44:13

a kind of big challenge. Almost

44:15

a model can't really tell you anything

44:17

at this point because this is the

44:20

data is so uninformative about the process

44:22

that we, yeah, there's lots of question

44:24

at the question at the moment

44:26

at the moment, and I get, and

44:29

I get, and I get, and I

44:31

get, I get, and I get, I

44:33

get, and I get, and I

44:35

get, and I get, and I get,

44:38

the output data is just too bad

44:40

to say much. We can design some,

44:43

you know, what if hypothetical models, but

44:45

I think that's much harder. I

44:47

think there's also just the technical challenge

44:49

that, you know, in terms of just

44:52

making sure that models you build are

44:54

without bugs, and then also edge cases,

44:56

another classic one that there's, there

44:58

can be sometimes some psychicalters, just things,

45:01

particularly if you're doing the kind of

45:03

delay processes. So one example, which I

45:05

think it was a sort of

45:07

communication one, but even if you have

45:10

an epidemic that's going up and you

45:12

suddenly stop it and you have a

45:14

delayed outcome like deaths, the peak in

45:17

when the epidemic stops isn't the

45:19

same as the peak in death because

45:21

you're doing a kind of delayed convolution,

45:23

we're doing it smooth out of lay

45:26

distribution. As a feature like that, you're

45:28

making sure that you've actually got

45:30

that relationship defined properly. And again, this

45:32

is I think why the move to

45:35

a lot more established libraries rather than

45:37

trying to make sure these things

45:39

are sort of bug-free in real-time. Okay,

45:41

yeah, yeah. And a question I often

45:44

get, you know, personally, and I'm guessing

45:46

you are getting a lot too, is,

45:48

okay, cool. I get uncertainty estimation,

45:50

you know, with the Bayesian models. Why

45:53

do I care? So

45:55

I think a lot of what

45:57

you want to do, particular decision

46:00

making. comes down to confidence and

46:02

evidence so particularly in in the

46:04

middle of an epidemic there's a

46:06

lot of things we don't know

46:08

with any confidence. So I guess

46:10

on the one hand you could

46:12

just ignore it and just go

46:14

for you know the point estimate

46:16

is it going up is it

46:18

going down but particularly if you

46:20

want to say you want to

46:22

ask is the epidemic under control

46:25

it's not very helpful to have

46:27

a yes-no always that you might

46:29

want to say yes is under

46:31

control how confident are you for

46:33

it is and again having that

46:35

uncertainty in a reproduction number, if

46:37

you're like, well, 100% of our

46:39

density is below one. And that's

46:41

what we had post-lockdowns and social

46:43

mixing day, for example, in the

46:45

UK, that there was uncertainty in

46:48

that distribution, but all of that

46:50

density was below one. So the

46:52

conclusion was we're very confident that

46:54

transmission is coming down. I think

46:56

similarly for some of the variants

46:58

we found that we found that

47:00

some of the variants we found

47:02

that you'd get uncertainty in the

47:04

estimates. So maybe it's 30% maybe

47:06

it. be very confident it is

47:08

more transmissible and I think it's

47:11

a difficult one because policy makers

47:13

sometimes love you know single answers

47:15

they don't want a kind of

47:17

vague but I think particularly if

47:19

your uncertainty lands either side of

47:21

a particular threshold that matters that

47:23

can in a way give you

47:25

more confident communicating of saying yeah

47:27

look this is definitely going up

47:29

or this is definitely almost definitely

47:31

on a different crop. Just it's

47:33

similar, you know, the clinical problem,

47:36

you look at the conference into

47:38

book, I think it's the equivalent

47:40

of that, and you want to

47:42

know, you know, how much can

47:44

you rely on this estimate? And

47:46

I think that's where the uncertainty

47:48

really comes in. Yeah, yeah, so

47:50

basically making sure that you're not

47:52

fooled by the variance of the

47:54

processes. Yeah, and I think especially

47:56

when you're dealing with exponential processes,

47:59

that you know, exponential processes, that

48:01

you know, exponential processes, that you

48:03

know, that you know, I was

48:05

going to accumulate. So there's something

48:07

that might feel quite small of

48:09

the transmission rates this. And actually

48:11

if it's slightly higher or slightly

48:13

lower, you get a very different

48:15

outcome. Even something, you know, say

48:17

it's a very simple example, each

48:19

person affects two others and you

48:22

cut transmission in half. So, you

48:24

know, each person affects one other,

48:26

just on one other, a tiny

48:28

amount of uncertainty there after, you

48:30

know, two months could be the

48:32

difference between a massive epidemic and

48:34

a handful of cases. you know

48:36

if you don't communicate that people

48:38

be asking well was a massive

48:40

epidemic when you said it would

48:42

it would be allowed based on

48:44

the best estimate. Yeah yeah yeah

48:47

that's definitely a good point in

48:49

I'm curious also to have your

48:51

to hear your thoughts about you

48:53

know the latest advancement step we've

48:55

seen in the last year in

48:57

artificial intelligence and large language models

48:59

because I'm guessing this is going

49:01

to have also an impact hopefully

49:03

for the best on epidemiology. So

49:05

yeah with these advancements how do

49:07

you see the future of the

49:10

field of epidemiology and and the

49:12

role of patient stance in it?

49:14

Yeah I think it's a huge

49:16

amount of They're really promising development.

49:18

I think a lot of it

49:20

at the moment that we're working

49:22

on in most others is trying

49:24

to find where do these solutions

49:26

work. I think essentially we've been

49:28

given this increasingly amazing toolkit, but

49:30

in many cases it wasn't necessarily

49:32

developed exact problems we're working on.

49:35

And so finding where the applications

49:37

work is going to be very

49:39

powerful, where are the ones that

49:41

is going to struggle more. And

49:43

so even... It's a bit of

49:45

AI or some more traditional machine

49:47

learning approaches that there might be

49:49

situations where if we're very interested

49:51

in the mechanism and we've got

49:53

some process we define our model,

49:55

perhaps that estimation or that prediction

49:58

approach. isn't optimal for actually what

50:00

we're trying to solve. But I

50:02

think equally, the pandemic re-showed, there

50:04

was a huge amount of data

50:06

out there that in many cases

50:08

we weren't able to interpret in

50:10

a meaningful way. So you might

50:12

have something like a social contact

50:14

and if it got by a

50:16

certain amount, but you put that

50:18

in a model and a very

50:21

meaningful change. But you might have

50:23

quite a lot of very noisy

50:25

data, which is giving some indication

50:27

about how people are behaving. But

50:29

you can't extract those features and

50:31

weigh them in a useful way

50:33

in the same sense that an

50:35

AI model could do. So I

50:37

think it's in a way to

50:39

find the range of problems. I

50:41

think broadly the challenge we have

50:43

for our works often that they're

50:46

quite rare events. So even what

50:48

do you what do you validate

50:50

against and what and what's your

50:52

input and what you kind of

50:54

outcome you kind of predict. But

50:56

I think within a epidemic especially

50:58

you get larger clinical data sets,

51:00

larger behavioral data sets of a

51:02

lot of value there. I think

51:04

also some of the the methods

51:06

like universal differential equations and other

51:09

things coming through where it's taking

51:11

that that sort of transmission model

51:13

structure but then incorporating things like

51:15

neural networks to to allow for

51:17

more complexity in understanding the patterns

51:19

that are kind of going on

51:21

alongside that I think there's a

51:23

lot of really interesting progress there

51:25

I think just also just more

51:27

generally in the field there's some

51:29

of the AI models that essentially

51:32

learning features that can I mean

51:34

by the forecasting is one example

51:36

where it's many many times faster

51:38

and less energy intensive for simulations.

51:40

I think again that kind of

51:42

you can find ways of approximating

51:44

more complex models. I think just

51:46

also just in terms of the

51:48

data that comes in I mean

51:50

a lot of outbreaks often describe

51:52

the narrative reports where it's kind

51:54

of like a few paragraphs and

51:57

so did this and went here

51:59

and did that. And one of

52:01

my colleagues did this nice prototyping

52:03

but equally on this. That's all

52:05

local models that can take those

52:07

quite difficult to interpret. Now it's

52:09

important to convert them to structured

52:11

data which you can then... Yeah,

52:13

basically, you know, like in a

52:15

lot of other fields, you would

52:17

like to see kind of a

52:20

better communication, but I think there's

52:22

a lot of work, really across

52:24

the spectrum, both in a lot

52:26

of other fields, you would like

52:28

to see kind of a better

52:30

communication between these. kind of models,

52:32

the LA models in the humans

52:34

in the loop, but clearly you

52:36

don't see these kind of models

52:38

being made entirely by artificial intelligence.

52:40

No, but we've tried it actually,

52:42

so even things like Copilot workspace,

52:45

which look, you try them out

52:47

on a simple problem and they

52:49

look really, really cool. So, yeah,

52:51

the idea that you can just

52:53

give it a code base and

52:55

tell it to do things. But

52:57

often for quite specific things, if

52:59

you say build me a model

53:01

with these features to do this,

53:03

I think because just the training

53:05

set, just doesn't include anything with

53:08

them, or very little with them,

53:10

that kind of problem. So if

53:12

you want an LLEM to build

53:14

you, to build you some JavaScript,

53:16

it's pretty good, because there's just

53:18

so much to train on. If

53:20

you want quite an inch compatible

53:22

model of an epidemic, it's struggles

53:24

in some way. So I think

53:26

finding the shape, you know, it's

53:28

great for, I've all these functions.

53:31

package them up and add the

53:33

documentation and this kind of stuff.

53:35

It makes a lot of tasks

53:37

faster. But I think, yeah, the

53:39

idea is she's going to do

53:41

science. I think it's maybe put

53:43

forward by people who've only worked

53:45

on a narrow set of scientific

53:47

problems. And there's probably some science

53:49

that's going to do well and

53:51

then there's some that's going to

53:53

really struggle with, hopefully not just

53:56

the boring bits. But we'll, I

53:58

think we need to, yeah, map

54:00

out where those gaps are. You

54:02

know, it's the same in my

54:04

feel, whether that's sports modeling or

54:06

or just, you know, statistical. modeling

54:08

in general where it's really funny

54:10

because if you ask an LLLM

54:12

what a hierarchical model is it

54:14

can explain into training well you

54:16

know that's like that's exactly what

54:19

I would explain my students but

54:21

then if you ask for Pymc

54:23

code of that the code the

54:25

model is not at all hierarchical

54:27

it's just a classic model you

54:29

know but the the L& will

54:31

like well this is a hierarchical

54:33

model but it's not. So I

54:35

definitely have to drive that back

54:37

and forth but it makes you

54:39

it makes you yeah more more

54:42

efficient also you know it can

54:44

like it helps me for instance

54:46

to kill my darlings maybe a

54:48

bit faster which is very important

54:50

in modeling that's always better to

54:52

do it in my experience with

54:54

a human but sometimes you don't

54:56

have someone at the same stat

54:58

level as you in your organization

55:00

or project so then you have

55:02

you have to do that on

55:04

your own and that can be

55:07

quite hard. I think there's something,

55:09

we're using it actually for things

55:11

like reviewing training materials, because sometimes

55:13

you want to throw at human

55:15

view, but sometimes you want the

55:17

first part of, you know, if

55:19

an applied field ecologists is reading

55:21

this, is there anything in there

55:23

that just is going to not

55:25

make sense or really, really obvious

55:27

things you want to fix. It

55:30

can just help accelerate a lot

55:32

of that kind of production process.

55:34

Okay. Okay. Yeah. That's actually, yeah.

55:36

That sounds very useful. So you've

55:38

been already very generous with your

55:40

time. So we're gonna I'm gonna

55:42

play us out here, but I'm

55:44

also curious to hear Your thoughts

55:46

about more educational perspective because you

55:48

do a lot as we've heard

55:50

a lot of public communication. So

55:52

Given your experience what educational initiatives

55:55

would you recommend to better prepare

55:57

next? generations of epidemiology. Yes, but

55:59

also policymakers and citizens in general.

56:01

Yeah, I think there's probably like

56:03

some specific angle within the audience,

56:05

which has become more general ones.

56:07

I mean, I think it's not

56:09

realistic to try and get people

56:11

to have a deep understanding of

56:13

epidemics any more than it's realistic

56:15

to have a very, very deep

56:18

understanding of kind of the unique

56:20

threats or something. But I think

56:22

there are certain features of epidemics

56:24

which a very important and very

56:26

often misunderstood. So I think one

56:28

aspect is exponential growth is a

56:30

concept that people find very difficult.

56:32

You look at who makes and

56:34

loses money in finance and there's

56:36

a definite divide in terms of

56:38

understanding that's a concept. And so

56:41

I think having more interest of

56:43

that across more people is very

56:45

helpful. Similarly, things like having lagged

56:47

outcomes that, you know, if you

56:49

have an event you care about

56:51

and then an effect that happens

56:53

later. That's something that's kind of

56:55

widely misinterpreted during the pandemic. And

56:57

yeah, I think it wasn't increasingly,

56:59

as code went on, it wasn't

57:01

just people who hold academic posts

57:03

in epidemiologists that were making a

57:06

lot of useful contributions. You had

57:08

a lot of people who were

57:10

adjacent industries who maybe, you know,

57:12

actually doing finance and other bits

57:14

of, you know, academic work or

57:16

even just, you know, mass teachers,

57:18

whatever doing. quite useful stuff because

57:20

they hadn't understand those concepts when

57:22

you get a feel for some

57:24

of those data problems that just

57:26

needed more eyes on them. So

57:29

I think for me that's where

57:31

a lot of value is. It's

57:33

like how do we have more

57:35

people who can just not get

57:37

very basic things wrong and just

57:39

have useful eyes on the problem

57:41

even if they don't know the

57:43

ins and outs exactly how you

57:45

calculate that specific prancer. I think

57:47

more generally though we're also just

57:49

seeing I think it's a challenge

57:52

for a lot of fields that

57:54

with the emergency AI with the

57:56

mode of flying the sort of

57:58

more complex understand of epidemics. I

58:01

think we are moving into a

58:03

world that's much harder to sort

58:05

of teach yourself everything from scratch.

58:07

I mean, you know, if you

58:10

think about even statistics as a

58:12

field, the sort of statistics that

58:14

practitioners do relative to what's important

58:16

schools is now very different. You

58:19

know, it's the sort of doing

58:21

kind of regression lines and the

58:23

things that, you know, I did

58:25

at a level. And I think

58:28

we're seeing that in a lot

58:30

of fields now, where actually the

58:32

cutting edge is so far detached.

58:34

partly challenges in communication because even

58:37

if you, a very interesting climate,

58:39

you can't, I can't go and

58:41

run a climate model in the

58:44

way that you might be able

58:46

to do a simple mathematical proof

58:48

or a simple statistical problem. So

58:50

I think there's that kind of

58:53

relationship of how do we build

58:55

trust and enough understanding of how

58:57

those fields work that people can

58:59

engage with them even though actually

59:02

that the kind of cutting edge

59:04

is now. so computationally intensive, in

59:06

some cases just so difficult to

59:08

explain in terms of the algorithms.

59:11

Yeah, I think like AI is

59:13

a problem example, but I think

59:15

there's a lot of those situations

59:17

where it feels like there's a

59:20

bit of a growing gap that

59:22

we need to bridge. Yeah, yeah,

59:24

yeah. Yeah, definitely. I mean, completely

59:27

agree with everything you just said.

59:29

That's a topic that's the other

59:31

to me, obviously, and... We've talked

59:33

about that several times on the

59:36

podcast. I think one of the

59:38

best episodes we've done, but that

59:40

was episode 50 with Sir David

59:42

Piegel Halter, only sir, he had

59:45

to have been on the podcast.

59:47

But yeah, that was a great

59:49

episode. David is an awesome communicator

59:51

also. So I'll put that episode

59:54

in the show notes for people

59:56

who want to dig deeper. one

59:58

of the episodes I recommend a

1:00:00

lot. And then this, the next

1:00:03

one, episode 51, with Aubrey Clayton

1:00:05

about his book. and the crisis

1:00:07

of modern science really recommend the

1:00:10

book and end the episode also

1:00:12

because these two together make a

1:00:14

great combination if you're interested in

1:00:16

epidemiology. Okay, well, I am. That

1:00:19

was awesome. Really, thank you so

1:00:21

much for taking so much time.

1:00:23

was going to be fascinating and

1:00:25

it was. So, thanks a lot.

1:00:28

Thanks a lot to Chris Wyment

1:00:30

again. But before letting you go,

1:00:32

of course, I'm going to ask

1:00:34

you the last questions. I ask

1:00:37

every guest at the end of

1:00:39

the show. One, if you had

1:00:41

unlimited time and resources, which problem

1:00:43

would you try to solve? That's

1:00:46

a big one. One of the

1:00:48

things coming out of COVID that

1:00:50

really struck me is with a

1:00:53

lot of infections, we're actually quite

1:00:55

unambitious, I think. You know, that

1:00:57

we put up with a lot

1:00:59

of disease in day life and

1:01:02

even free COVID, if you look

1:01:04

at a lot of adverse for

1:01:06

medicine when you're ill, it's, you

1:01:08

know, just keep going, keep going.

1:01:11

And I think we saw a

1:01:13

lot of indications during COVID for

1:01:15

some of the sort of technologies

1:01:17

and approaches. it weren't lockdowns but

1:01:20

were actually much proficient and even

1:01:22

just like the work that I've

1:01:24

sort of done on things like

1:01:26

digital tools. So I think we've

1:01:29

got these little signals that we

1:01:31

could be much much better in

1:01:33

how we tackle these problems and

1:01:36

I think that's something that would

1:01:38

require quite a lot of resource

1:01:40

and time to do effectively. But

1:01:42

even like I've got young children

1:01:45

and yeah there's a lot of

1:01:47

kids that kind of hospitalized with

1:01:49

a lot of infections that We

1:01:51

could understand, we could test about,

1:01:54

and I think we rely a

1:01:56

lot on, we wait for a

1:01:58

vaccine to be developed, but I

1:02:00

think I've always just wondered, yeah.

1:02:03

could we do something a bit

1:02:05

clever? Can we go to all

1:02:07

this technology? I mean, there's a

1:02:09

US colleague who, during COVID, said,

1:02:12

you know, this is our Apollo

1:02:14

mission. Can we actually do something

1:02:16

extremely innovative and ambitious, COVID? I

1:02:19

think vaccines were amazing, some of

1:02:21

the treatments coming down, but we

1:02:23

didn't, I think, solve that, that

1:02:25

much earlier, a problem of what

1:02:28

to do around infection. So yeah,

1:02:30

I'd love us to live in

1:02:32

a different world where we can

1:02:34

actually. Yeah, yeah, yeah, definitely share

1:02:37

that passion and objective. And if

1:02:39

you had, if you could have

1:02:41

dinner with a great scientific mind,

1:02:43

dead alive or fictional, who would

1:02:46

it be? So I think recently

1:02:48

for a project, I mean, reading

1:02:50

up a lot about William Gossett

1:02:52

called AK Student. who develops tests

1:02:55

and works at Guinness, but actually

1:02:57

digging more into his work, he

1:02:59

was a really interesting character because

1:03:02

there was a lot of conflict

1:03:04

with Fisher in terms of outlook.

1:03:06

And Fisher was very much from

1:03:08

the kind of academic focus of,

1:03:11

you know, you recruit knowledge and

1:03:13

you want very high confidence in

1:03:15

that knowledge and that's why you

1:03:17

have the sort of thresholds and

1:03:20

experiments of science that he's been

1:03:22

bored. Gossett was much more of

1:03:24

a pragmatist. Yeah, he was working

1:03:26

for a big business and I

1:03:29

mean, there's one situation where he

1:03:31

had a P value of point,

1:03:33

um, point one three and he

1:03:36

said, you know, that's very good

1:03:38

evidence. You know, if it's a

1:03:40

business and it doesn't cost much

1:03:42

and we can explore further, it's

1:03:45

worth going forward. Well, as you

1:03:47

know, Fisher would have had that.

1:03:49

Okay, if it's, if it's not

1:03:51

hitting the five percent, we're not

1:03:54

interested, we're not interested. And we're

1:03:56

not interested. maybe a part of

1:03:58

statistics that got suppressed I think

1:04:00

probably a lot of the 20th

1:04:03

century. I think Fisher and Co.

1:04:05

probably one hour. in many ways

1:04:07

in terms of imposing those those

1:04:09

criteria and in some cases throwing

1:04:12

away a lot of evidence and

1:04:14

I mean although it wasn't so

1:04:16

it was basically this was very

1:04:19

anti-basian but I think that that

1:04:21

making use of limited information the

1:04:23

gossip was you know it was

1:04:25

very adamant in some cases I

1:04:28

think you had budget to get

1:04:30

two data points or something and

1:04:32

it was still that I want

1:04:34

to do something like that. So

1:04:37

I think that would be a

1:04:39

very interesting person to dig into

1:04:41

the strategy. It also just sounds

1:04:43

like he was just a very

1:04:46

nice guy relative to Fisher and

1:04:48

some of the others at the

1:04:50

time. So yeah, I think that

1:04:52

the kind of different outlook of

1:04:55

where you set the bar and

1:04:57

actually, you know, what are you

1:04:59

trying to do with statistics? Are

1:05:02

you trying to kind of get

1:05:04

perfect knowledge or are you actually

1:05:06

just trying to make better decisions?

1:05:08

Wasn't that hard to be a

1:05:11

nicer guy than Fisher apparently? But

1:05:13

yeah, no, I mean, I definitely

1:05:15

resonate with what you were saying

1:05:17

because all my models, most of

1:05:20

my models, I do them not

1:05:22

for academic use, but for companies.

1:05:24

And yeah, like, there is a

1:05:26

lot of things you have to

1:05:29

be able. to prioritize. I think

1:05:31

that's one of the most important

1:05:33

skills to have as a modeler,

1:05:35

especially if you're in a small

1:05:38

team, right? If you're in a

1:05:40

big project with a lot of

1:05:42

modelers, you can explore a lot

1:05:45

of path at the same time.

1:05:47

But if you're in a small

1:05:49

team, then you have to really

1:05:51

be able to set the priorities

1:05:54

and see what path you want

1:05:56

to explore first. That's often a

1:05:58

metaphor used to explain what the

1:06:00

modeling process is. It's like being

1:06:03

lost in a desert and you're

1:06:05

trying to find your way out

1:06:07

in the most efficient way is

1:06:09

usually to explore a lot of

1:06:12

path and see which ones are

1:06:14

successful. There can be several of

1:06:16

them. There can be just one

1:06:18

of them. There can be zero

1:06:21

sometimes. But also exploring a path

1:06:23

that ends up not being successful

1:06:25

is actually very informative. because then

1:06:28

that means the people behind you

1:06:30

won't make the same mistakes and

1:06:32

they won't go down that path.

1:06:34

So to explore these paths you

1:06:37

can do it alone if you

1:06:39

don't have any more people that's

1:06:41

just going to take you more

1:06:43

time but you have to do

1:06:46

it or you can do it

1:06:48

with several people simultaneously. But that's

1:06:50

where the idea of priorities, also

1:06:52

very important because your priorities are

1:06:55

going to dictate which path you

1:06:57

go down first. Yeah,

1:07:00

and I think it's that

1:07:02

that I said that the

1:07:04

priority is in the focus

1:07:06

that I think to kind

1:07:08

of angle which you know

1:07:10

maybe in the kind of

1:07:13

the pursuit perfection We don't

1:07:15

always get that balance right

1:07:17

in it particularly when it's

1:07:19

kind of academic academic research

1:07:21

interacting with very fast problems

1:07:23

Right. Yeah. Yeah. Awesome. Well

1:07:26

Adam Let's call you to

1:07:28

show that was this was

1:07:30

in Absolutely pleasure to have

1:07:32

you here on the show

1:07:34

as usual. I will link

1:07:36

to your website and your

1:07:39

socials and your books in

1:07:41

the show notes for people

1:07:43

who want to dig deeper.

1:07:45

Thank you again Adam for

1:07:47

taking the time and being

1:07:49

on this show. Yeah, that's

1:07:51

not me good shot. Be

1:07:54

sure to rate, review and

1:07:56

follow the show on your

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favorite. put catcher and visit

1:08:00

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1:08:02

about today's topics as well

1:08:04

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1:08:07

to help you reach true

1:08:09

patient state of mind. That's

1:08:11

run-based stats.com. Our theme music

1:08:13

is good-basin by Baba Brittman,

1:08:15

fit M.S. and Megaran. Check

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out his awesome work at

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Baba Brittman.com. I'm your host

1:08:22

Alex Andorra. You can follow

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me on Twitter at Alex

1:08:26

Undor andora like the country.

1:08:28

You can support the show.

1:08:30

and unlock exclusive benefits by

1:08:32

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1:08:35

you so much for listing

1:08:37

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1:08:39

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1:08:41

change your predictions after taking

1:08:43

information and if you're thinking

1:08:45

I'll be less than amazing.

1:08:48

Let's adjust those expectations. Let

1:08:50

me show you how to

1:08:52

be a good lazy. Change

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Let's get them on a

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From The Podcast

Learning Bayesian Statistics

Are you a researcher or data scientist / analyst / ninja? Do you want to learn Bayesian inference, stay up to date or simply want to understand what Bayesian inference is?Then this podcast is for you! You'll hear from researchers and practitioners of all fields about how they use Bayesian statistics, and how in turn YOU can apply these methods in your modeling workflow.When I started learning Bayesian methods, I really wished there were a podcast out there that could introduce me to the methods, the projects and the people who make all that possible. So I created "Learning Bayesian Statistics", where you'll get to hear how Bayesian statistics are used to detect black matter in outer space, forecast elections or understand how diseases spread and can ultimately be stopped.But this show is not only about successes -- it's also about failures, because that's how we learn best. So you'll often hear the guests talking about what *didn't* work in their projects, why, and how they overcame these challenges. Because, in the end, we're all lifelong learners!My name is Alex Andorra by the way, and I live in Estonia. By day, I'm a data scientist and modeler at the PyMC Labs consultancy. By night, I don't (yet) fight crime, but I'm an open-source enthusiast and core contributor to the python packages PyMC and ArviZ. I also love election forecasting and, most importantly, Nutella. But I don't like talking about it – I prefer eating it.So, whether you want to learn Bayesian statistics or hear about the latest libraries, books and applications, this podcast is for you -- just subscribe! You can also support the show and unlock exclusive Bayesian swag on Patreon!

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