Degrees of Freedom (Independent-Samples t-Test)

Multiple Comparisons

Null and Alternative Hypotheses for the Independent-Samples t-Test

Formula for the Independent-Samples t-Test

Example of an Independent-Samples t-Test

What is the primary purpose of conducting an independent-samples t-test?

Arrange the steps in the correct logical sequence for conducting a statistical analysis to compare the average scores of two distinct groups of participants.

A researcher recruits 60 university students and randomly assigns 30 to a mindfulness training group and 30 to a no-training control group. After four weeks, she measures each participant's self-reported stress score (on a 0–100 scale). Because each participant appears in only one group, she plans to use an independent-samples t-test to determine whether the two groups differ in mean stress scores. Is this an appropriate choice of statistical test for this study?

Match each component of a research study to its specific analytical role when determining if there is a significant difference between two groups using an independent-samples $t$-test.

You are designing a research study to evaluate whether a new 'peer-tutoring program' results in higher final exam scores than 'independent study'. Arrange the following steps in the correct logical sequence to construct a valid research protocol that appropriately utilizes an independent-samples $t$-test to compare the two groups.

An independent-samples $t$-test is used to determine if there is a significant difference between the means of three or more distinct groups.

A researcher wants to determine whether there is a statistically significant difference between the average scores of two completely separate groups of participants. Which of the following best explains why an independent-samples $t$-test is the appropriate statistical procedure for this analysis?

A researcher uses an independent-samples $t$-test to evaluate whether there is a significant difference between the means of two separate groups. If it is later discovered that the same individuals were actually measured in both groups, the researcher must judge the results of the analysis as _____ because the assumption of distinct samples was violated.

Match each research design component with the scenario that describes its application for an independent-samples $t$-test.

A clinical psychologist wants to determine if a new therapy reduces depression. They assign one group of participants to receive the therapy and a separate, independent group to a waitlist control. To evaluate whether the difference between the mean depression scores of these two distinct groups is statistically significant, they must conduct an _____ $t$-test.