Lab04

Variables, Design & Notation

Dr. Gordon Wright

25 October, 2022

Getting clarity on your variables

Individual mini-dissertations

Must conform to a 2x2 ANOVA with a single continuous DV

Lab activities

Formalise your individual design

More specific

Notation

We use a notation system to refer to these designs:

2x2 = Two-way ANOVA. There are two IVS, the first IV has two levels, the second IV has 2 levels. There are a total of 4 conditions, 2x2 = 4.

2x3 = Two-way ANOVA. There are two IVs, the first IV has two levels, the second IV has three levels. There are a total of 6 conditions, 2x3 = 6

4x4 = Two-way ANOVA. There are two IVs, the first IV has 4 levels, the second IV has 4 levels. There are a total of 16 condition, 4x4=16

2x3x2 = Three-way ANOVA.There are a total of three IVs. The first IV has 2 levels. The second IV has 3 levels. The third IV has 2 levels. There are a total of 12 condition. 2x3x2 = 12.

3 ‘flavours’ of 2x2 ANOVA

2bx2b - Between-subjects/Factorial ANOVA

2wx2w - Within-subject/Repeated Measures ANOVA

2bx2w or 2wx2b - Mixed ANOVA

You will be using one of these (all supported by SPSS Exercise 1 and 2)

JAMOVI is a reasonable alternative to SPSS (also supported in Exercise 1 and 2)

The 3 effects possible in a 2x2 ANOVA

Main effect of IV1

Main effect of IV2

Interaction of IV1*IV2

therefore 8 possible ‘outcomes’ of a 2x2 ANOVA

  • no IV1 main effect, no IV2 main effect, no interaction
  • IV1 main effect, no IV2 main effect, no interaction
  • IV1 main effect, no IV2 main effect, interaction
  • IV1 main effect, IV2 main effect, no interaction
  • IV1 main effect, IV2 main effect, interaction
  • no IV1 main effect, IV2 main effect, no interaction
  • no IV1 main effect, IV2 main effect, interaction
  • no IV1 main effect, no IV2 main effect, interaction

graph key for following charts

  • 1 = there was a main effect for IV1.
  • ~1 = there was not a main effect for IV1
  • 2 = there was a main effect for IV2
  • ~2 = there was not a main effect of IV2
  • 1x2 = there was an interaction
  • ~1x2 = there was not an interaction

Bar charts

https://crumplab.com/statistics/10-MixedANOVA.html#fig-10bar22

Line plots

https://crumplab.com/statistics/10-MixedANOVA.html#fig-10lines22

PS52007D Research Methods VLE