R'A' Fisher Evolutionary Biologist

1
An introduction to the BIOM 333 course
The course text
http//www.oup.co.uk/best.textbooks/biology/grafen
hails/
2
Preliminaries
Basic themes

• Model formulae - learn the language of statistics
• Geometry - pictures are nice, nicer than algebra
• Computers - do the donkey work

Together, these allow you to learn the statistics
you need to operate as a biologist.
3
Preliminaries
This Term
1 An introduction to Biom 333 course and
analysis of variance 2 Regression 3 Models,
parameters and GLMs 4 Using more than one
x-variable 5 Designing experiments 6 Combining
continuous and categorical variables 7
Interactions -- getting more complex 8 Checking
the models I independence
4
What is an Analysis of Variance?
5
What is an Analysis of Variance?
6
What is an Analysis of Variance?
SSY Sum of squares of Y sum of the
squares of the dotted lengths i.e. of the
deviation of datapoint from grand mean
7
What is an Analysis of Variance?
SSY Sum of squares of Y sum of the
squares of the dotted lengths i.e. of the
deviation of datapoint from grand mean
8
What is an Analysis of Variance?
SSE Sum of squares of Error sum of
the squares of the dotted lengths i.e. of
the deviation of datapoint from group mean
9
What is an Analysis of Variance?
SSY Sum of squares of Y sum of the
squares of the dotted lengths i.e. of the
deviation of datapoint from grand mean
10
What is an Analysis of Variance?
SSE Sum of squares of Error sum of
the squares of the dotted lengths i.e. of
the deviation of datapoint from group mean
11
What is an Analysis of Variance?
SSF Sum of squares of Fertiliser sum
of the squares of the dotted lengths (x10)
i.e. of the deviation of group mean from grand
mean
12
What is an Analysis of Variance?
13
What is an Analysis of Variance?
SSY Total sum of squares SSE Error sum of
squares SSF Fertiliser sum of squares (SSY
SSF SSE) EMS SSE / 27 FMS SSF / 2 Under
H0, EMS and FMS are approximately equal F
EMS/FMS should be about 1
14
What is an Analysis of Variance?
SSY Total sum of squares SSE Error sum of
squares SSF Fertiliser sum of squares (SSY
SSF SSE) EMS SSE / 27 FMS SSF / 2 Under
H0, EMS and FMS are approximately equal F
EMS/FMS should be about 1
15
Analysis of Variance in Minitab
- from Minitab supplement - availability - SAS
and SPSS
16
Analysis of Variance in Minitab
17
Analysis of Variance in Minitab
18
Analysis of Variance in Minitab
19
Analysis of Variance in Minitab
20
Geometry and Analysis of Variance
21
Geometry and Analysis of Variance
22
Geometry and Analysis of Variance
23
Geometry and Analysis of Variance
24
Geometry and Analysis of Variance
25
Geometry and Analysis of Variance
26
Geometry and Analysis of Variance
27
Geometry and Analysis of Variance
28
Geometry and Analysis of Variance
29
Geometry an Analysis of Variance
30
Geometry and Analysis of Variance
31
Last words

• statistics is not maths and is not too hard
• learn it while youve got all the help around you
• isnt it exciting that a sum of squares is a sum
  of squares?

32
Last words

• statistics is not maths and is not too hard
• learn it while youve got all the help around you
• isnt it exciting that a sum of squares is a sum
  of squares?

Next week Regression Read Chapter 2