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Based on the principles of experimental design, evaluate the researcher's proposed solution. Should the researcher discard the data to achieve equal group sizes? Explain why or why not.
Case context: A researcher is conducting an experiment with participants, assigning them to a treatment or control group using a strict coin-flipping procedure. After all participants have completed the study, the researcher realizes the treatment group has people and the control group has people. The researcher is worried that the unequal sample sizes will ruin the experiment and considers deleting the data of participants from the treatment group to make the groups equal.
Question: Based on the principles of experimental design, evaluate the researcher's proposed solution. Should the researcher discard the data to achieve equal group sizes? Explain why or why not.
Sample answer: No, the researcher should not discard the data. Although having equal-sized groups is statistically more efficient, unequal sample sizes are generally not a significant issue in experimental design. Researchers should never throw away collected data simply to equalize group sizes.
Key points:
- The researcher should not discard the data from the participants.
- Unequal sample sizes are generally not a significant issue.
- Researchers should never throw away already collected data just to achieve equal sample sizes.
Rubric: The student must explicitly state that the researcher should not discard the data. The explanation must demonstrate comprehension that while equal sizes are statistically efficient, unequal sizes are not a serious problem, and discarding valid collected data to balance groups is strictly advised against in the text.
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Research Methods in Psychology - 4th American Edition @ KPU
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