Statistics Chapter 11

A repeated measures t-test has a sample of n = 14 participants with ΣD = -56. What is the mean (MD) for this sample?

-4

A repeated measures t-test has a sample of n = 36 participants with MD = 4.10 and SS = 560. What is the variance (s2) for this sample?

16

Which of the following is most likely to use repeated measures design?

Evaluate the effectiveness of biofeedback on reducing pain before and after treatment

For a repeated measures t-test, the null hypothesis states:

The entire population will have mean difference of μD = 0

A two related samples t test was conducted for SlimFast (a weight loss shake). A total of 40 participants were recruited. The study ended with a MD = -10. What does this tell you about the study?

The participants lost weight

Compared to an independent-measures design, a repeated-measured study is more likely to find a significant effect because it reduces the contribution of variance due to ______.

individual differences

In a repeated-measures experiment, each individual participates in one treatment condition and then moves on to a second treatment condition. One of the major concerns in this type of study is that participation in the first treatment may influence the participant's score in the second treatment. This problem is called ______.

order effects

A health coach tested the effectiveness of a new harm reduction behavioral therapy for nicotine cessation among college students. A sample of n = 16 college students participated in the 6-week study and at the end of the study the mean difference in number of times students used cigarettes or e-cigarettes was MD= - 1.25 with a standard error SM = .5. What is the correct t-score and decision for this study using α=.05, two tailed test?

t(15) =-2.50, reject the null hypothesis

A researcher believes that a new biofeedback technique that uses virtual reality will impact patient pain. She a recruits a sample of n = 9 patients for her study and asks them to rate their pain before and after the new biofeedback technique. Assume that the biofeedback scores are normally distributed with a MD = -2.25 and SS = 72. What is the correct t-score and decision using an α = .05 two tailed test?

t(8) = -2.25, p >.05 Fail to reject the null hypothesis

Outside influences, a disadvantage of repeated measure t-tests, refers to

things like extraneous variables that happen to all participants across the separate trials