Statistical Modelling

Problem Sheet
BIOM40

2

5 – Statistical Modelling – 2020

Introduction

For this Problem Sheet, you will be analysing some of the data provided through the Model seeks Data link
on the ELE page under Task

1

.3.1).

I have exported the data for you and I have also done a bit of cleaning-up (but not too much!). You can find
the data as a Comma seperated values (.csv) file on the ELE page.

You will see that I have kept the description of the tasks deliberately general. This means that you have a lot
of freedom in how you choose to approach each one of them. What I expect from you is to show off your
statistical modelling and R skills by applying what you have learned during the lectures and especially the
practicals. I am looking for creativity, originality, clarity and comprehension. For more information, see the
marking criteria on the ELE page.

Please note that during the lecture and practical Q&A sessions we will NOT answer questions that are
directly related to this problem sheet.

What to submit

You are required to perform all of the tasks listed on the next page. Remember that there are often many
ways of achieving the same thing, but simpler is usually better. You are limited to 3 pages (including your
code and figures), so you will have to be both selective and concise, and you have to think carefully about
what you present.

You will need to provide both the R code (but of course only the code that worked. . . ) and the output. There
are two alternative ways of doing this:

1. Copy-paste everything into a Word document. Use a fixed-width font like Courier or Courier New
for both your R code and the output. Make sure that you annotate your code so that someone else
(i.e. me) can follow why you did what, and to show that you have understood what you did. To
copy-paste a figure, go to the Plots tab in the bottom-right panel and click on Export → Copy to
Clipboard…. Alternatively, you can use Save as Image… or Save as PDF… and import this file
into Word. There are no specific requirements with respect to font size, line spacing or margins, but
please use common sense and keep it clear and easy to read. Save the final document as a PDF.

2. You can use R Markdown, which provides a powerful tool to combine R code, output and any other text,
images, equations, etc., into a single document. As a matter of fact, most of the documents for this
module (including this one) are written using R Markdown! Although I think that on the long-term
learning R Markdown might be worth it, it is yet another new thing to learn and you probably have
plenty of other things to do as well. It is therefore completely up to you whether you use R Markdown
or not. If you would like to know more, have a look at the R Markdown website.

How to submit

Submit a PDF via eBART following the instructions on the ELE page. The deadline is November 30 at
12:00 (noon).

1

https://vle.exeter.ac.uk/mod/url/view.php?id=1415157

http://vle.exeter.ac.uk/course/view.php?id=9280

https://vle.exeter.ac.uk/pluginfile.php/1992879/mod_label/intro/Marking%20criteria%20BIOM4025%20Problem%20sheet

http://rmarkdown.rstudio.com

http://vle.exeter.ac.uk/course/view.php?id=9280

Tasks

We have data for a diverse set of variables, including both continuous and categorical variables, and while
some are expected to be normally distributed, others probably are not.

Task 1

Choose a dependent variable and one or more predictor variables and formulate (in words) the hypothesis
that you would like to test. Be creative!

Task 2

Use (generalised) linear (mixed) modelling to test this hypothesis. Provide the code that you used, as well as
any relevant output. Add comments (using #) to your code that allow me to understand why you did what.

Task 3

Write one or more sentences for the Results section of a scientific article in which you summarise your most
important result. It does not matter if your P-value is smaller or larger than 0.05!

Task 4

Provide a publication-ready figure that illustrates this result.

2

Introduction
What to submit
How to submit
Tasks
Task 1
Task 2
Task 3
Task 4

99

m

m

:00

10 Yes

0 2 2 0 2

00

I am not born in the UK

6 cm

0 cm

Yes

15

1

2 2 2 0 0

Female

8 cm

Yes

NA Yes 0 I like both 0 1 3 0 1

Female

cm

23:00

Yes

NA No 4

0 0 4 0 0

Female 1998

No 30 30

1 Cats 1 0 3 0 0

Female

I am not born in the UK

0

No NA NA No 2 Dogs 0 0 2 0 0

Female

I am not born in the UK

NA NA

08:30 Yes 2 2 No 1 I like both 1 1 7 7 2

Male 1996

5 ft 6

07:00 Yes 0 20 No 2 I like both 1 2 5 0 2

Male 1998

2

NA NA 23:00 08:00 Yes 30 30 Yes 1 I like both 1 1 2 0 0

Female

5 ft 5 5 ft 10 5 ft 6 23:00 08:00 Yes 10 10 No 1 I like both 0 1 7 6 6

Female 1999

5 ft 6 5 ft 7

07:00 Yes 0 0 Yes 1 I like both 0 2 2 0 2

Female 1999 Devon 5 ft 8

22:00 07:00 Yes NA NA Yes 2 I like both 1 0 6 0 2

Female

I am not born in the UK

23:30

Yes

20 Yes 1 Dogs 2 0 4 0 0

Male 1998

NA NA 23:00

Yes NA NA No 2 I like both 0 1 3 0 3

Male 1995

Yes 15 15 Sometimes

Dogs 1 0 4 0 1

Female 1995

5 ft 8

5 ft 1 23:00 08:00 Yes 25

No 10 I like both 0 1 3 0 3

Female 1998

175 cm 162 cm 23:30 07:30 Yes NA NA No 10

1 1 4 0 3

Male 1998 Cornwall 6 ft 2 6 ft 1 5 ft 9 23:30 09:00 Yes

14 No 1 I like both 1 0 6 6 0

Male 1998 Herefordshire

NA NA

Yes 10 10 No 1 Dogs 0 1 7 3 5

Male 1997 Greater London

Yes

15 No 3 Dogs 0 1 6 4 2

Female 1998 Greater London

170 cm

22:30

Yes 20 20 Sometimes 1 Dogs 1 1 7 2 2

Male 1998

6 ft 2

5 ft 4

No NA 15 No 1 I like both 1 0 4 3 0

Male 1998

6 ft 4 5 ft 11 5 ft 5

08:00 Yes 15 15 Yes 1 Dogs 0 1 5 4 0

Female 1995

5 ft 7

22:30

Yes 15 16 No 1 I like both 0 0 7 3 3

Female 1998 I am not born in the UK 5 ft 5 5 ft 7 5 ft 6 23:30

Yes 0 0 Yes 1 I like both 2 1 4 0 3

Female 1997

5 ft 7 5 ft 11 5 ft 3 23:30 08:30 Yes NA NA No 0 I like both 4 2 4 0 0

Female 1999 Buckinghamshire 5 ft 5 5 ft 11 5 ft 4 00:30

Yes 20 15 Yes 1 I like both 1 1 4 4 1

Male

Devon 5 ft 10

5 ft 7 02:00 06:00 No NA 50 No 10 I like both 0 1 7 0 5

Female

173 cm NA NA 22:30

Yes 25 25 Yes 2 I like both 3 0 2 0 1

Female 1998 Hertfordshire 5 ft 7 5 ft 10 5 ft 6 23:00 09:00 Yes 0 45 Yes 3 Dogs 1 0 5 1 2
Female 1998 I am not born in the UK 158 cm NA

Yes 20 30 No 0 I like both 0 1 0 0 0

Female 1998

5 ft 4 NA NA 00:00 09:00 Yes 0 40 No 2 Cats 0 3 5 3 2

Female 1998

NA NA

08:00 Yes NA NA No 1-2 I like both 1 1 5 0 2

Female 1995

5 ft 7 6 ft 0 5 ft 6 23:00 08:00 Yes 2 2 No 7 I like both 0 0 5 0 0

Female 1999 Greater London 5 ft 5 5 ft 11 5 ft 5

Yes 20 15 Sometimes 2 I like both 1 0 5 0 0

Female 1998 I am not born in the UK 158 cm 173 cm 156 cm 01:00 08:30 Yes 25 10 Yes

I like both 1 0 6 0 2

Female 1996 I am not born in the UK 5 ft 4 6 ft 0 5 ft 2 01:00 09:00 Yes 15 15 No 1 I like both 0 1 5 0 0
Female 1997 I am not born in the UK 170 cm

160 cm NA NA Yes 20 18 Sometimes 2 I like both 1 0 3 0 0

Female

Surrey

6 ft 1 5 ft 5 22:00 08:30 Yes 20 20 Yes 3 I like both 1 0 7 0 3

Female 1998

6 ft 0 164 cm 02:00

Yes 25 20 No 1 I like both 1 0 3 0 0

Male 1997 I am not born in the UK

1.70 m

00:00 08:00 Yes

13 Yes 1 Dogs 0 2 1 0 1

Female

5 ft 8

00:00

No NA

No

I like both 1 2 3 0 1

Female 1995 Greater London

157 cm 00:30 09:00 Yes NA NA Sometimes 1 I like both 4 1 5 0 0

Male 1999 Greater Manchester 6 ft 1 NA NA 02:00 10:00 No 25 25 Yes 0 Dogs 1 1 2 0 0
Female 1998

5 ft 2 5 ft 9 5 ft 5 01:00 09:00 Yes 20 20 No 0 Dogs 1 0 7 0 1

Female 1998 Somerset NA NA NA 23:00 07:30 Yes NA NA No NA I like both 0 2 4 0 4
Female

I am not born in the UK 5 ft 6 6 ft 1

00:30 08:30 No 10 10 Yes 3 I like both 1 0 3 3 1

Female 1997 I am not born in the UK

1.70 m 1.65 m

No NA NA Yes 1 Dogs 1 0 6 6 0

Female 1998 Greater London 5 ft 3 6 ft 2 5 ft 3 23:30 08:30 No 30 30 Yes 1 I like both 1 0 2 0 1
Female 1996 I am not born in the UK 5 ft 6 NA NA 02:00 10:00 No 0 20 Yes 2 Dogs 1 0 5 5 0
Female 1996 Hertfordshire 5 ft 10 6 ft 5 ft 9 22:00 08:00 Yes 0 10 No 2 I like both 1 1 5 5 0
Male 1998 Greater Manchester 6 ft 0 6 ft 2 5 ft 6 23:00 07:30 Yes 30 30 No 4 I like both 2 1 3 0 4
Female 1994

165 cm 175 cm 161 cm 22:00 09:30 Yes NA 20 Yes 1 Dogs 1 1 5 0 3

Female 1996 I am not born in the UK 160 cm 180 cm 159 cm 02:00

Yes 15 15 No 2 I like both 1 0 0 0 0

Female 1998

5 ft 7 6 ft 0 5 ft 5 00:00 09:30 No 30 30 No 0 Dogs 0 2 2 0 0

Female 1998 Wales 5 ft 2 5 ft 8 5 ft 4 00:30 09:30 Yes 0 15 Yes 1 Dogs 1 0 4 0 2
Female 1991 Surrey 5 ft 3 NA NA

:30

06:00 No 30

No 2 Dogs 1 1 7 3 2

Female 1996 Greater London

23:30

Yes NA 45 Yes 1 I like both 0 3 2 0 0

Male 1994 I am not born in the UK

NA NA 22:30 06:30 Yes 0 15 No 2 I like both 1 1 0 0 0

Female 1998 Greater London 5 ft 3 5 ft 9 5 ft 6 23:00

Yes 5 5 Yes 1 Dogs 0 1 4 3 0

Female 1998 I am not born in the UK 165 cm 180 cm 163 cm 22:00 08:30 No 30 30 Yes 3 I like both 0 0 6 0 0
Female 1998

5 ft 6 5 ft 7 5 ft 6

08:00 Yes 0 15 No 1 Dogs 0 2 3 0 3

Female 1997 Greater London 158 cm 170 cm

21:30

Yes NA 45 Yes 1 I like both 1 0 3 0 0

Male 1998

5 ft 8

23:30 09:30 Yes NA 25 Yes

I like both 2 2 5 5 1

Female 1993 I am not born in the UK 160 cm 172 cm 162 cm

09:00 Yes 20 18 Yes 2 I like both 0 2 2 2 2

Male 1998

6 ft 0 5 ft 8 5 ft 7 00:30 09:30 Yes 15 15 Yes 3 Dogs 1 0 5 3 0

Female 1997 Surrey 5 ft 4 NA NA 00:30

Yes NA 50 No 5 Dogs 0 1 6 0 2

Female 1996

5 ft 7 6 ft 0 5 ft 5 23:00 08:00 Yes 25 25 Yes 1 Dogs 2 0 4 0 0

Female 1995 I am not born in the UK 1.64 m

23:00 08:00 Yes 0 25 No 1 Cats 1 1 6 0 1

Female 1997 East Sussex 5 ft 5 5 ft 8 5 ft 7 00:00 08:20 Yes 0 20 Yes 0.25 Dogs 1 1 4 0 2
Female 1996

5 ft 7 NA 5 ft 5

08:00 Yes 0 15 No 1 Dogs 1 1 2 0 0

Female 1998 Greater London 180 cm

167 cm 01:00 09:30 Yes 10 8 Sometimes 0 I like both 0 4 4 0 0

Female 1998

1.65 m NA NA 22:30 09:00 Yes 30 30 Yes 1 I like both 1 1 1 0 0

Male 1992 Buckinghamshire

00:00

Yes 15 15 No 2 I like both 1 1 5 3 2

Female 1996 West Sussex 5 ft 5 5 ft 7 5 ft 4 23:00 07:00 Yes 20 20 No 2 Cats 1 0 4 4 1
Female 1996 I am not born in the UK 161 cm 170 cm 175 cm

07:30 No 5 NA Yes 1 I like both 1 2 4 0 0

Female 1996 Greater London

177 cm 23:30 07:00 Yes NA NA No 1 I like both 1 1 5 0 4

Male 1995 Cambridgeshire

6 ft 1 NA 01:00 09:30 Yes 3 3 No 0 I like both 0 1 4 0 0

Female 1999 I am not born in the UK 5 ft 6 5 ft 7 5 ft 4 01:30 09:00 Yes

0.1 Yes 3 I like both 0 0 7 0 4

Male 1998 Greater London 198 cm 180 cm 170 cm 22:30

Yes 10 10 No

Dogs 0 3 7 0 2

1993 I am not born in the UK 180 cm NA NA 00:00 08:00 Yes 11 12 No 0.5 I like neither 0 1 5 0 4

Female Devon 5 ft 5 NA NA

07:00 Yes NA NA No 2 Cats 1 1 3 0 2

Female 1998 I am not born in the UK 5 ft 2 5 ft 10 5 ft 3 23:30 08:30 Yes NA NA Yes 0 I like both 0 0 4 4 1
Female 1995 I am not born in the UK

175 cm

23:00 08:00 Yes 5 5 Yes 2 I like both 0 0 2 0 2

Male 1997 Oxfordshire

5 ft 8 00:00 07:30 Yes 0 0 No 2 Dogs 1 0 5 0 5

Male

Greater London 6 ft 0 5 ft 10 5 ft 8

Yes

120 No 1 Dogs 1 0 3 2 0

Female 1998 East Sussex 5 ft 6 5 ft 9 5 ft 6 23:30 09:30 Yes 15 15 No 0 I like both 0 2 2 0 1
Female 1996

5 ft 4 5 ft 8 5 ft 3 23:00 08:30 Yes 0 25 Yes 1 I like both 0 1 3 0 2

Female 1998 I am not born in the UK

NA 1.64 m

07:30 Yes NA 20 Yes NA I like both 0 1 3 0 1

Female 1995

5 ft 10 6 ft 1 5 ft 6

Yes 15 10 Yes 1 Cats 1 2 5 4 0

Female 1996 Greater London

6 ft 4 5 ft 10 23:00 08:00 Yes 0 0 Sometimes NA I like both 0 1 3 0 0

Female 1999 Hertfordshire 5 ft 6 6 ft 1 5 ft 3 01:00 08:30 Yes 10 10 No 0 I like both 1 1 5 0 0
Female 1996 I am not born in the UK 5 ft 6 6 ft 0 5 ft 5 23:30 10:30 Yes 0 0 No 2 I like both 1 1 2 0 0
Female 1997

159 cm 5 ft 10

23:30

No NA 10 Yes 1 I like both 1 2 4 1 0

Female 1995 I am not born in the UK 162 cm NA NA

No 5 5 Yes 2 I like both 2 1 3 0 2

Male 1991 I am not born in the UK 6 ft 2 5 ft 8 5 ft 6 01:00 09:15 Yes 8 8 No 6 I like both 1 1 5 0 3
Male 1992 I am not born in the UK 187 cm 180 cm 175 cm 23:00

No 0 NA No 1 I like both 0 1 0 0 0

Female 1996 I am not born in the UK

00:00 07:00 Yes 8 10 Yes 1 Dogs 0 1 0 0 0

Female 1994

5 ft 8 5 ft 11 5 ft 5 23:00

Yes 30 30 Sometimes 2 I like both 2 2 3 0 0

Female 1999 Kent 5 ft 4 6 ft 3 5 ft 0 23:30 09:00 Yes 0 20 No 1 Dogs 1 1 1 0 1
Female 1998 I am not born in the UK 1.72 m

10:30 Yes 5 5 No 1 Dogs 0 1 2 0 0

Female 1997 Greater London 5 ft 2 5 ft 6 5 ft 5 23:30 08:15 Yes 20 25 No 3 I like both 1 2 2 0 1
Male 1995 Greater London 5 ft 10 5 ft 11 5 ft 3 23:00 09:00 Yes 20 25 No 1 I like both 0 0 3 0 3
Female 1993 Kent 5 ft 9 6 ft 1 5 ft 10

10:00 Yes 15 15 Yes 1 I like both 0 1 3 0 0

Female 1996 NA 5 ft 2 NA NA 23:00 08:00 Yes 0 5 Yes 1 Dogs 3 0 0
Male 1997 Wiltshire 5 ft 6 5 ft 10 5 ft 3 23:00 08:00 Yes 10 11 No 1 Dogs 1 0 4 3 1
Female 1998 I am not born in the UK 5 ft 3 6 ft 0 5 ft 5 23:45 06:30 Yes 20 0 No 0 Dogs 0 0 6 0 0
Female 1995

6 ft 1 5 ft 6 23:00 07:00 Yes 12 14 Yes 1 Dogs 3 0 6 0 0

Male 1997 Cambridgeshire 185 cm

157 cm 01:30 07:45 No 13 13 No 1 Dogs 1 1 3 0 2

Female 1997 Norfolk 5 ft 6 NA NA

07:00 No 30 30 Yes 1 I like both 1 2 7 0 0

Female 1997 I am not born in the UK

1.60 m 23:00 07:30 Yes 14 17 Yes 2 I like both 0 0 4 4 1

Female 1998 Oxfordshire NA NA NA 23:00 07:30 Yes 30 20 No 0.5 I like both 0 1 3 0 0
Female 1995 I am not born in the UK 5 ft 5 5 ft 5 5 ft 3 23:30 07:30 Yes NA NA Yes 2 I like both 0 1 7 1 2
Male 1999 I am not born in the UK 191 cm 185 cm 175 cm 00:00 07:15 Yes 5 5 No 1 I like both 0 1 6 3 2
Female 1993 I am not born in the UK

NA NA

06:00 Yes 18 21 Sometimes 1 I like both 1 3 2 0 0

Male 1996

168 cm 160 cm 164 cm

07:30 Yes 25 20 No 1 Dogs 1 1 4 2 2

Female 1999

5 ft 7 6 ft 0 5 ft 6 01:00 10:00 Yes 0 0 Yes 0 Cats 1 0 0 0 0

Male 1994 Kent 178 cm NA NA

08:30 No 13 15 No 1 I like both 1 0 6 0 0

Gender

Year of birth

Where were you born

Height

Height father

Height mother

Bed time

Waking up time

Breakfast

Commute today

Commute yesterday

Glasses

Number of books

Pet

Brothers

Sisters

Exercise

Gym

Running

Male

1

7

I am not born in the UK

1.

8

0

1.70 m

1.

6

5

2

3

07:00

Yes

10

1-2

Dogs

Female

20

18

192 cm

17

23:00

08:00

15

No

I like both

1998

Greater London

16

189 cm

163 cm

00:

30

07:30

NA

1999

Somerset

16

4

156 cm

161 cm

07:

50

25

Cats

East Sussex

5 ft 5

5 ft 8

5 ft 2

22:00

08:50

Sometimes

1985

5 ft 7

5 ft 1

5 ft 9

02:00

08:30

1996

5 ft 6

23:30

Devon

5 ft

11

5 ft 10

00:00

Cornwall

6 ft

1995

Hertfordshire

Surrey

5 ft 4

00:30

6 ft 1

5 ft 11

1997

173 cm

176 cm

167 cm

09:15

40

Buckinghamshire

175 cm

09:00

Herefordshire

180 cm

185.5 cm

162 cm

23:01

07:55

0.2

Scotland

6 ft 2

32

Cambridgeshire

158 cm

I like neither

14

187 cm

22:30

06:00

1.88 m

1.65 m

1.64 m

22:10

06:10

12

160 cm

157 cm

06:30

West Sussex

6 ft 4

02:30

12:00

Oxfordshire

23:58

Reading

5 ft 3

5 ft 0

05:

45

07:45

Wales

08:20

1993

6 ft 0

1981

Greater Manchester

06:45

155 cm

01:00

09:30

Essex

Cumbria

164 cm

23:15

County Durham

01:30

10:30

1.5

185 cm

1991

168.5 cm

Bristol

178 cm

10:00

1.75 m

1.60 m

13

1992

West Yorkshire

5 ft 6.5

5 ft 4.5

07:20

33

0.25

159 cm

165 cm

Worcestershire

1994

5 ft 6

1.76 m

02:55

11:50

Wiltshire

13:00

Dorset

21

35

157.5 cm

182.8 cm

160.2 cm

08:05

191 cm

07:15

Cheshire East

00:15

172 cm

07:10

Kent

5 ft 1

0.5

5 ft 0.75

2-3

23:54

South Yorkshire

08:38

North Yorkshire

1.85 m

1.55 m

Poole

23:40

198 cm

Norfolk

183 cm

177 cm

168 cm

06:55

01:50

179 cm

190 cm

6 ft 3

0.1

08:15

0-1

Other

23:45

169 cm

166 cm

6 ft 3

5ft 11

1988

22:05

06:15

120

Northumberland

1.62 m

00:45

West Midlands

02:15

06:49

5 ft 9.5

Merseyside

5 ft 2.5

06:18

00:51

08:47

06:03

1.69 m

1.72 m

1.6 m

Bath and North East Somerset

05:00

1.74 m

1.68 m

02:20

03:00

North Somerset

5 ft 8.5

188 cm

03:30

1.61 m

1.71 m

150 cm

20:00

West Berkshire

22:40

Derbyshire

22:32