Unrelated T-tests

Question 1

What are the data requirements for unrelated t-test?

Answer 1

Two sets of values from continuous variables, taken from two different samples (e.g males vs females)
Differences between the sets of scores should ideally form a normal distribution.

Question 2

What variables are required for unrelated t-test?

Answer 2

IV - group to which the cases belong to I.e. Gender or condition
DV

Question 3

In words, what is the independent t-test formula?

Answer 3

T= sample 1 mean - sample 2 mean divided by the SE of differences between sample means

Question 4

Why does the formula for independent t-test need to be more complicated?

Answer 4

Because there are two different groups and it has to:
Account for SE in both samples
Account for differences in sample sizes
Calculate the difference between the pairs of sample means
Add the two standard errors together

Question 5

How to do an independent t-test in SPSS?

Answer 5

Analyze -> compare means -> independent samples t-test
Move DV into text variable and IV into grouping variable
Enter codes for each group into define groups

Question 6

What is a unrelated t-test?

Answer 6

Unrelated/uncorrelated/independent

Used with unrelated or between-participants design.
For when two sets of scores are obtained from different samples.