Learn Before
A researcher is evaluating two strategies to try and increase the absolute value of their statistic in a one-sample -test. Strategy A involves refining their measurement tool to decrease the sample standard deviation (), while Strategy B involves purposefully reducing the sample size () to save money. Evaluate which strategy is mathematically sound for increasing the absolute value of based on the formula , and briefly explain why.
Question: A researcher is evaluating two strategies to try and increase the absolute value of their statistic in a one-sample -test. Strategy A involves refining their measurement tool to decrease the sample standard deviation (), while Strategy B involves purposefully reducing the sample size () to save money. Evaluate which strategy is mathematically sound for increasing the absolute value of based on the formula , and briefly explain why.
Sample answer: Strategy A is sound because decreasing the sample standard deviation () decreases the value of the overall denominator (). Dividing the numerator by a smaller denominator yields a larger absolute statistic. Strategy B is incorrect because decreasing the sample size () decreases the square root of , which causes the denominator to become larger, leading to a smaller absolute value.
Key points:
- Evaluates Strategy A as mathematically effective for increasing the absolute t-value.
- Evaluates Strategy B as ineffective or counterproductive.
- Explains that decreasing SD makes the denominator smaller, which increases the quotient.
- Explains that decreasing N makes the denominator larger, which decreases the quotient.
Rubric: The response should evaluate Strategy A as the correct approach and Strategy B as incorrect. It should justify this by explaining that a smaller SD reduces the denominator (increasing the overall t-value), while a smaller N increases the denominator (decreasing the overall t-value).
0
1
Tags
KPU
Research Methods in Psychology - 4th American Edition @ KPU
Related
Which of the following is the correct formula for calculating the statistic in a one-sample -test?
In the one-sample -test formula (), each mathematical component represents a specific concept used in psychological research. Match each term with the concept it quantifies.
Based on the mathematical relationships in the one-sample -test formula , arrange the following research scenarios from the one that results in the smallest absolute value (order 1) to the one that results in the largest absolute value (order 4).
A researcher evaluates two potential modifications to a study design to increase the magnitude of the statistic (). Modification A is to quadruple the sample size (), and Modification B is to double the difference between the sample mean and the population mean (). The researcher concludes that both modifications will have an identical impact on the calculated value, specifically doubling its magnitude. This evaluation is correct.
In the formula for a one-sample -test, the sample mean () is subtracted from the hypothetical population mean () to calculate the numerator.
In the one-sample -test formula , what does the final calculated value represent conceptually?
A cognitive psychologist is testing a new memory-enhancement technique. The average number of words recalled by the general population on a specific test is 15. A sample of 36 students using the new technique recalls an average of 18 words with a sample standard deviation of 9. Using the one-sample -test formula , the statistic for this sample is _____.
A clinical psychology researcher wants to test whether an intervention reduces anxiety scores below the national average. The hypothetical population mean anxiety score is . After the intervention, a sample of participants has a mean anxiety score of with a sample standard deviation of . Using the one-sample -test formula , calculate the statistic. Show your work step-by-step and explain how the numerator and the denominator each contribute to the final calculated value.
Analyze Dr. Smith's error in the calculation. How does failing to take the square root of the sample size () mathematically distort the denominator of the statistic formula, and what impact does this specific error have on the resulting value? Provide the correct calculation to support your analysis.
A researcher is evaluating two strategies to try and increase the absolute value of their statistic in a one-sample -test. Strategy A involves refining their measurement tool to decrease the sample standard deviation (), while Strategy B involves purposefully reducing the sample size () to save money. Evaluate which strategy is mathematically sound for increasing the absolute value of based on the formula , and briefly explain why.