Stats - Week 3

Question 1

Independent Sample T-test

Answer 1

What if our “effect” or “model” is that some things (groups) are different, this test for this.

Independent T-Test is used to… examine two means from separate entities (e.g., experimental group vs control group) to see whether we can say they are from a single population.

Looks at diff between two means and tells us if the diff is significant. Which tells us they are from two diff populations.

EXAMPLES:

• control placebo group in research
• gender
• left vs. right hand
• political groups

Question 2

Test Statistic Look At

Answer 2

effect/error

Question 3

Assumptions for t-test

Answer 3

Sampling distribution of dependent variable is normal. For independent t-tests, is for the mean of each group.

Interval/ratio measurement.
(for DV)

Independent Samples:
The DV scores of one group don’t influence scores of other group
(on Dependent Variable).

Homogeneity of Variance /
Aka “equal variances”:
The population variance (omega2) of DV scores for the two groups are equal; (omega2-1 = omega2-2)