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Samples t tests - Coggle Diagram
Samples
t
tests
Comparing groups
Null=difference in means are =
means are =
Design
one IV
Nominal IV
Only 2 groups/levels/catagories
one DV
interval or ratio DV
assumptions
normal distribution
visual inspection
Shapiro-Wilk test
Null=normal distribution
Homogeneity of variance
variance around the mean is equal
Levene's test
untrustworthy when variance is unequal
Null=group variance is equal
Don't want test to be significant
SPSS
check for normality
use split file to seperate groups
run Sample t test
Check for equal variance
Done when running sample
t
test
Effect size
Use Cohen's d
Measures how different the means are in SDs.