Inferential Statistics Psychology

Mann Whitney Test

Difference – ordinal – independent 

Calculated value < or equal to the critical values = significant 

Number of participants 
groups of N 
NA and NB (each are number off participants) 

Wilcoxon test

Difference – ordinal – repeated 

Calculated value < or equal to critical value 

N number of participants 

Unrelated T Test 

Difference – interval – independent 

Calculated value > or equal to the critical values = significant 

Df = N-1 (working out t) for the table 

Related T Test 

Difference – interval – repeated 

Calculated value > or equal to the critical values = significant 

Df = N-2 (working out t) for the table 

Chi-Squared test 

Association – Nominal – independent 

Calculated value > or equal to the critical values = significant 

Df = in book but is (rows – 1) x (columns – 1) these are in the contingency table 

 

Spearman’s rho 

Correlation – ordinal – whatever design 

Calculated value > critical value = significant 

N = number of participants 

+/- is irrelevant 

Pearsons 

Correlation – interval – whatever design 

Calculate value > critical value = significant 

Df = N-2 

+/- is irrelevant