4. T-tests Flashcards
(11 cards)
What are the two kinds of t-tests?
Independant and Paired sample
What is the criteria for an independant t-test?
Between subjects
Continuous data (interval/ratio)
Normally distributed
Must have homogeneity of variance
What is the criteria for a paired sample t-test?
Within-subjects
Continuous data (interval/ratio)
Normally distributed
What is homogeneity of variance?
Variance between groups is equal
How do we test for homogeneity of variance?
Levene’s test
What does it mean if Levene’s test is signifcant?
Homogeneity of variance is violated
What test do we carry out if HoV is significant?
Welch’s test
What is included when writing up an independant samples t-test?
Cohen’s D
Confidence intervals
What are the parameters for Cohen’s D?
0.2- small effect size
0.5- medium effect size
0.8- large effect size
What are confidence intervals?
Interval which is expected to contain the parameter being estimated
What does a narrow CI mean?
Its a precise estimate
