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Based on the principles of statistical validity, what specific calculation must Dr. Lin conduct, and why does the number of experimental conditions in her study make this calculation critical?
Case context: Dr. Lin is planning a psychological experiment to test whether a new memory technique works better than traditional studying. She knows her study will involve three different experimental conditions. However, she is unsure how many participants she needs to recruit to be confident that her study will find a statistically significant relationship if one truly exists.
Question: Based on the principles of statistical validity, what specific calculation must Dr. Lin conduct, and why does the number of experimental conditions in her study make this calculation critical?
Sample answer: Dr. Lin must conduct a power analysis. The likelihood of finding a statistically significant relationship depends heavily on both the sample size and the number of experimental conditions, so she needs this calculation to ensure she recruits enough participants to reliably test her hypothesis effectively.
Key points:
- Identifies that a power analysis must be conducted.
- Explains that the likelihood of finding a significant relationship depends on the number of experimental conditions.
- Notes that the calculation will determine the exact sample size needed across the conditions.
- States that this ensures sufficient statistical power to test the hypothesis effectively.
Rubric: The student must identify that Dr. Lin should conduct a power analysis and explain that the number of experimental conditions heavily influences the likelihood of finding a statistically significant relationship, thus dictating the needed sample size.
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Research Methods in Psychology - 4th American Edition @ KPU
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