Journal Article 1: Eakman, A. M., Schmid, A. A., Henry, K. L., Rolle, N. R., Schelly, C., Pott, C. E., & Burns, J. E.  (2017). Restoring effective sleep tranquility (REST): A feasibility and pilot study. British Journal of Occupational Therapy, 80, 350–360. doi:10.1177/0308022617691538

Learning Objectives: 9-1: The key components necessary to test cause and effect. | 9-2: How to design an experiment. | 9-5: How to balance internal and external validity in an experiment.

Summary: This is a pilot correlational study on a sleep intervention.

Questions to Consider:

1. Which requirements of causality are met by this study, and which requirement is not met?
2. How might one design a simple experiment that follows up on the results of this study?
3. How might one balance internal and external validity in the follow-up experiment?

Journal Article 2: Choudhary, D., Bhattacharyya, S., & Joshi, K. (2017). Body weight management in adults under chronic stress through treatment with Ashwagandha root extract: A double-blind, randomized, placebo-controlled trial. Journal of Evidence-based Complimentary & Alternative Medicine, 22, 96–106. doi:10.1177/2156587216641830

Learning Objectives: 9-1: The key components necessary to test cause and effect. | 9-2: How to design an experiment. | 9.3: How to manipulate an independent variable (IV). | 9-4: How to measure a dependent variable (DV).

Summary: This article reports the method and results of an experiment comparing the efficacy of Ashwagandha root extract to a placebo.

Questions to Consider:

1. What was the independent variable (IV) in this study and how did the researchers manipulate the IV?
2. What was the dependent variable (DV) in this study and how did the researchers measure the DV?
3. What procedures did the researchers use to minimize or avoid threats to internal validity?

Journal Article 3: Green, J. (2010). Points of intersection between randomized experiments and quasi-experiments. The Annals of the American Academy of Political and Social Science, 628, 97–111. doi:10.1177/0002716209351517

Learning Objectives: 9-1: The key components necessary to test cause and effect. | 9-2: How to design an experiment. | 9-5: How to balance internal and external validity in an experiment. | 9-6: Limitations of experimental design.

Summary: This is a review of the benefits and limitations of quasi-experiments and “pure” experiments.

Questions to Consider:

1. What are the similarities and differences between quasi-experiments and “pure” experiments?
2. What are the threats to internal validity in quasi-experiments?
3. What are the threats to external validity in pure experiments?