Repeated Measures Designs

Difference Score

Example of a Dependent-Samples t-Test

When is it most appropriate to use a dependent-samples t-test in a research study?

A cognitive psychologist measures the reaction times of 40 participants while they complete a task in a quiet room, and then measures the reaction times of those exact same 40 participants while they complete the task in a noisy room. The psychologist should use a dependent-samples t-test to analyze the differences in reaction times.

Match the following terms associated with the dependent-samples $t$-test to the description that best captures their conceptual role in psychological research.

A psychologist is conducting a within-subjects study where participants' memory performance is measured both before and after a specific intervention. To perform a dependent-samples $t$-test on this data, the researcher must transform the paired scores into a testable format. Arrange the following steps in the correct logical order of analysis.

The dependent-samples $t$-test is also commonly referred to as the paired-samples $t$-test.

In a within-subjects psychology experiment, a researcher uses a dependent-samples $t$-test to analyze the data. Which of the following best explains the conceptual logic of how this test processes the participants' scores from two different conditions?

A researcher is critiquing a study that measured 30 participants' reaction times before and after a specific cognitive intervention. The researcher argues that the original analysis was flawed because it failed to account for the fact that the two sets of scores are not independent. To correctly evaluate this pretest-posttest data and account for the systematic relationship between the measurements, the researcher should have used a(n) _____-samples $t$-test.

A researcher is planning a study and must select the appropriate statistical test. Match each research scenario to the correct conclusion about whether a dependent-samples t-test is appropriate and why.

The dependent-samples t-test is conceptually a special case of the one-sample t-test because it first computes a _____ for each participant by subtracting one of their scores from the other, and then tests whether the mean of those computed values is significantly different from zero.

A graduate student is reviewing a peer's research report that claims a dependent-samples t-test was the correct statistical analysis for the study. Order the steps the graduate student should follow to evaluate whether that claim is justified.

Define the dependent-samples $t$-test and state its alternative name. Under what two research designs is this statistical test particularly appropriate, and how does it function conceptually in relation to another type of $t$-test?

Explain why a dependent-samples $t$-test is the appropriate choice for analyzing the difference in mean estimation accuracy in this scenario, and describe how this test conceptually functions in relation to a one-sample $t$-test.

A cognitive psychologist is conducting a within-subjects experiment to compare how participants perform on a reading task under two distinct conditions: once with background music playing, and once in silence. Identify the specific statistical test they should use to compare the performance means under these two conditions and apply the conceptual definition to justify this choice.