Exam 11: The T Test for Two Related Samples

A repeated-measures study and an independent-measures study both produce a t statistic with df = 20.The repeated-measures study used more subjects than the independent-measures study.

The estimated standard error in the denominator of the repeated-measures t statistic measures the average mean difference that is expected for a sample selected from a population with a zero mean difference.

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.What is this problem is called?

A researcher obtains t(20)= 2.00 and M_D = 9 for a repeated-measures study.If the researcher measures effect size using the percentage of variance accounted for,what value will be obtained for r²?

A set of n = 16 difference scores has a mean of M_D = 4 and a variance of s² = 36.Cohen's d for this sample is d = 4/6.

For a repeated-measures study comparing two treatment conditions,a researcher obtains Cohen's d = 0.50 for a sample of n = 4 scores with a variance of s² = 16.What is the value of the sample mean?

A repeated-measures study and matched-subjects study both produce t statistics with df = 20.The repeated-measures study used more participants.

A repeated-measures study comparing two treatments with a sample of n = 4 participants produces M_D = 3 with SS = 48 for the set of difference scores.What is the repeated-measures t statistic for these data?

If a set of n = 9 difference scores has a mean of M_D = 3.5 and a variance of s² = 36,then the standard error for the sample mean difference is 4 points.

For the repeated-measures t statistic,df = _____.

Although a repeated-measures study measures two scores for each participant,the sample mean and variance are computed using only one score for each participant.

A research report describing the results from a repeated-measures t test states that "t(22)= 1.71,p > .05." From this report,what was the outcome of the hypothesis test?

One advantage of a repeated-measures design is that it typically requires fewer participants than an independent-measures design.

In general,if the variance of the difference scores increases,what will happen to the value of the t statistic?

For a repeated-measures study,if other factors are held constant,then an increase in the size of the sample will increase measures of effect size.

What is indicated by a large variance for a sample of difference scores?

In a repeated-measures study comparing two treatments with a sample of n = 15 participants,the researcher measures two scores for each individual to obtain a total of 30 scores and the repeated-measures t statistic has df = 29.

A researcher reports df = 18 for a repeated-measures t statistic.This research study used a total of n = 19 participants.

If other factors are held constant,which of the following sets of data is most likely to produce a significant value for the repeated-measures t statistic?

A researcher conducts a repeated-measures study to evaluate a treatment with a sample of n = 16 participants and obtains a t statistic of t = 1.94.The treatment is expected to increase scores and the sample mean shows an increase.Which of the following is the correct decision for a hypothesis test using α = .05.