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Statistics without maths for psychology
Exercise 2
A researcher, Dr Kid, is interested in whether boys and girls differ in the ability to perceive colours.
She thinks that girls will be better than boys at perceiving differences in colours from a very early age.
She therefore tests two different age groups (5-year-olds and 11-year-olds) on a standard colour perception
test and compares the performance (marked out of 10) of boys and girls. The data are presented
below:
5-year-olds 11-year-olds
Boys Girls Boys Girls
4 6 4 8
3 5 2 9
4 6 3 9
5 4 4 8
9 6 7 7
1 7 5 10
0 8 4 9
2 6 3 10
3 5 2 8
3 4 2 6
4 6 4 9
5 3 5 8
1. What sort of design is this?
2. What are the IVs and DV?
3. Input the data into SPSS and conduct an ANOVA.
4. What are the F-values and associated probabilities of the main effects and any interactions?
5. Are any of these effects probably not due to sampling error? Which ones?
6. What are the magnitudes of effects for the main effects and interactions?
7. Conduct simple effects analyses to fi nd out if there was any improvement in colour perception with
age for the boys and then do the same analysis for the girls.
Multiple choice questions
1. How would you describe a 2 × 2 × 4 ANOVA?
(a) One IV with three conditions
(b) One IV with four conditions and one IV with two conditions
(c) One IV with four conditions and two IVs with two conditions
(d) One IV with 16 conditions