Diagnose the statistical error in the lead author's conclusion. Based on your understanding of -values and replication, what must the researchers consider before estimating the true likelihood of replication?
Case context: A research team conducts an experiment on a novel cognitive behavioral therapy technique for generalized anxiety disorder. They analyze their data and find a statistically significant reduction in anxiety scores with a -value of . In their discussion section, the lead author writes, 'Given our -value of , we can be confident there is a probability that other clinics will successfully replicate our significant results if they use the exact same therapy protocol.'
Question: Diagnose the statistical error in the lead author's conclusion. Based on your understanding of -values and replication, what must the researchers consider before estimating the true likelihood of replication?
Sample answer: The lead author has fallen for the misconception that the probability of replication is equal to . Calculating to get is an incorrect way to determine replication chances. To properly estimate the likelihood of a successful replication, the researchers must consider the statistical power of the planned replication study, which is typically much more demanding and is not directly provided by the original study's -value alone.
Key points:
- Identify that the author incorrectly used the formula to find replication probability.
- Diagnose the replication claim as a statistical misconception.
- State that a low -value () is not a guarantee of future replication.
- Explain that actual replication probability requires adequate statistical power.
Rubric: Full credit is awarded if the student identifies the fallacy and states that statistical power must be considered to estimate actual replication probability.
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Research Methods in Psychology - 4th American Edition @ KPU
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Diagnose the statistical error in the lead author's conclusion. Based on your understanding of -values and replication, what must the researchers consider before estimating the true likelihood of replication?
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