Exam 9: Experimental Designs: Within-Subjects Design

History, maturation, and instrumentation are especially threatening to studies when _____.

What is an advantage of the between-subjects design versus the within-subjects design?

For a within-subjects study comparing two treatments, A and B, a researcher expects that practice in the first treatment will improve the participants' scores in the second treatment. If the order of treatments is counterbalanced, then the practice will ____.

A matched-subjects design attempts to gain the advantages of a within-subjects design, although it actually compares different groups of participants.

A group of college students is participating in a memory study that involves performing the same task each day under different circumstances; however, as each day goes by, the students are obviously getting more comfortable with completing the task. Which threat to internal validity has confounded this study?

Randomly assigning participants to treatment conditions is not a part of within-subjects experiments.

Identify two time-related factors that can threaten the internal validity of a within-subjects research study. In each case, explain how the factor could be a confounding variable.

Dr. Feliciano is conducting a study of sleep on children's activity level that takes place over several days; however, Halloween falls in the middle of his study, and he notices that on Halloween, the children are especially active during his observation. Which threat to internal validity has confounded this study?

Using a Latin square to counterbalance a within-subjects experiment ensures that every possible ordering of treatment conditions is used.

A way to control for order effects in a within-subjects experiment is to use ____.

It is impossible to have order effects with a between-subjects design.

Which research design involves measuring the same group of participants in two different treatment conditions?

A Latin square design is used to determine the order of treatments that will be used in a within-subjects experiment comparing five treatments labeled A, B, C, D, and E. How many groups of participants will receive treatment E as the first treatment?

The advantages of within-subjects designs solve the disadvantages of between-subjects designs and vice versa.

What are the two major threats to internal validity in within-subjects experiments?

What is a time-related threat to internal validity for a within-subjects experiment?

What is a big advantage of using a multiple-treatment design?

If one or more of the treatments in an experiment is expected to have a large and long-lasting effect that could influence the participants' scores in later treatments, the best strategy is to use a between-subjects design.

How many groups of participants would be needed to partially counterbalance four treatment conditions?

Random assignment is used to control order effects in a within-subjects experiment.