The Mann Whitney U test

what does mann whitney U test?

whether there is evidence for a significant difference between scores in 2 conditions based on ranks (NP alternative for independent t-test)

steps of Mann Whitney U test:

1. formulate hypothesis

2. collect data

3. p-value from SPSS

4. accept or reject

5. what do we or do we no have evidence for?

expand collect data steps:

1. rank the data irrespective of which group it was in

2. calculate the sum of ranks in each condition (take ties into account)

3. what is the smallest that each sum of ranks could be? (add small numbers → 1,2,3)

4. how far is our sum of ranks above this (difference between our sums of ranks and smallest possible sum)

5. the mann whitney U statistic is the smaller of the conditions

alleged