Exam 10: Testing Means: Related-Samples T Test With Confidence Intervals

Which of the following is a type of related samples design in which different participants are actually observed in each group,but treated statistically as if they are the same persons in each group.

The degrees of freedom for the related samples t test is the number of pairs of participants minus one,and not always the total number of participants minus one.

As the value of the test statistic for a related samples t test increases,the likelihood of deciding to retain the null hypothesis also increases.

The related samples t test makes tests concerning the difference between pairs of measured scores.

A researcher asks a sample of brothers and sisters to rate how positive their family environment was during childhood.In this study,the differences in ratings between each brother and sister pair were compared.The type of design described here is called a

The degrees of freedom for the related samples t test is the number of difference scores minus one.

A researcher tests how well participants know their spouse while under hypnosis,and again without hypnosis.It was hypothesized that participant responses would be more accurate (greater number of correct responses)when under hypnosis.The mean number of correct responses was M = 5.30 under hypnosis and M = 3.40 without hypnosis in a sample of 30 participants.If the estimated standard error for difference scores was 2.52,then what is the decision at a .05 level of significance (two-tailed test)?

A professor compares scores on a competency exam among students at two times during a single semester.What type of t test is most appropriate for this study?

A researcher conditions rats to fear a tone that was sounded just prior to a brief shock.To measure fear following this conditioning,she records the number of lever presses by each rat in the presence and in the absence of the tone.It was hypothesized that reduced lever pressing in the presence of the tone was evidence for a conditioned fear response in rats.If the researcher tested this hypothesis at a .05 level of significance (two-tailed test),then what is her decision if she computes t = ñ2.842 in a sample of 8 rats.

Compared to the two-independent sample t test,the related samples design decreases

To compute the related samples t test,we assume independence within groups,but not between groups.

The assumptions for a related samples t test are the same as those for the two-independent sample t test.

A study in which 26 participants are observed two times is associated with 26 degrees of freedom for a related samples t test.

A researcher computes d = .12,which is a small effect size.

Using APA format,which value is typically given in parentheses when reporting the results for a t test?

Selecting related samples increases standard error and reduces power.

How does the test statistic differ for a t test using the repeated measures versus the matched samples design?

What are the degrees of freedom for the related samples t test?

A researcher conducts a study in which the population variance of difference scores between two groups is unknown.What type of t test is most appropriate for this study?

An example of matching by experimental manipulation would be if we matched participants based on their gender (male,female).