Learning Check, T-tests
1. A research article reports results of a study using a t test for dependent means as "t(16) = 2.67, p < .05." This means
a. the results were inconclusive.
b. there were 16 subjects.
c. the t score was 16.
d. the t score was 2.67.
2. Testing subjects before and after an experimental manipulation is
called a __________ design.
3. A research article reports results of a study using a t test for dependent means as "t(38) = 3.11, p < .01." This means
a. the result is significant.
b. the result is not significant.
c. a one-tailed test was used.
d. the critical value for .01 alpha was 3.11.
4. Which equations have the following structure:
A deviation from a mean divided by a standard deviation?
Answers, LC T-tests
2. repeated-measures, OR within-subjects, OR pretest-posttest
4. equation for Z-score: X - M / SD
hypothesis-test when pop variance known:
Z= X-bar - Mu / SE-means
t-test for single sample (Mu known)
t(df)= X-bar - Mu / SM [est SE]
t-test for dependent means
t(df)= X-bar(diff) - Mu(diff) / SM (mean diff)