Identify which of the three main research designs (experimental, quasi-experimental, or non-experimental) this study represents. Explain how its design features place it on the spectrum of internal validity relative to the other two designs.
Case context: A health psychologist wants to evaluate if a workplace wellness seminar reduces employee stress. Because of company policies, the psychologist cannot randomly assign employees to groups. Instead, they implement the seminar at one office location and compare it to a second office location that does not receive the seminar. They measure stress levels at both locations after one month.
Question: Identify which of the three main research designs (experimental, quasi-experimental, or non-experimental) this study represents. Explain how its design features place it on the spectrum of internal validity relative to the other two designs.
Sample answer: This study is a quasi-experimental design. It has lower internal validity than a true experiment because participants were not randomly assigned to the two locations, meaning pre-existing differences between the offices could explain differences in stress. However, it has higher internal validity than a non-experimental design because it still introduces an intervention (the wellness seminar) and compares it against a control group, rather than simply measuring variables without any manipulation or comparison group.
Key points:
- The study represents a quasi-experimental research design.
- It lacks random assignment of participants, making its internal validity lower than a true experiment.
- It has higher internal validity than non-experimental research because it still compares a manipulated intervention to a control.
Rubric: Grading Rubric: - Correctly identifies the study as a quasi-experimental design. - Explains why it is lower than experimental: lack of random assignment of participants. - Explains why it is higher than non-experimental: it utilizes some experimental structure/manipulation (comparing an intervention to a control) rather than no manipulation or control.
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Research Methods in Psychology - 4th American Edition @ KPU
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