Short Answer

In the calorie-estimate and weight study (N=22N = 22), Pearson's rr was calculated as .21-.21. Analyze why the researcher compared the absolute value of the correlation coefficient (.21.21) rather than the raw value (.21-.21) to the critical value (.444.444) when determining significance.

Question: In the calorie-estimate and weight study (N=22N = 22), Pearson's rr was calculated as .21-.21. Analyze why the researcher compared the absolute value of the correlation coefficient (.21.21) rather than the raw value (.21-.21) to the critical value (.444.444) when determining significance.

Sample answer: Because the researcher conducted a two-tailed test, the critical region is split between both positive and negative directions, corresponding to critical values of ±.444\pm.444. Using the absolute value (.21.21) simplifies the comparison to the positive critical value (.444.444) and is mathematically equivalent to confirming that the raw coefficient of .21-.21 falls within the non-significant range between .444-.444 and .444.444.

Key points:

  • Explain that a two-tailed test establishes critical boundaries in both directions (i.e., ±.444\pm.444).
  • Explain that using the absolute value allows a direct comparison to the positive critical value.
  • Explain that checking if the absolute value is less than the critical value is equivalent to checking if the raw coefficient falls between the negative and positive critical values.

Rubric: The answer should analyze that a two-tailed test has two critical values (±.444\pm.444) and that comparing the absolute value of the correlation coefficient (.21.21) to the critical value (.444.444) correctly determines whether the sample correlation falls within the rejection region in either direction.

0

1

Updated 2026-05-27

Contributors are:

Who are from:

Tags

KPU

Research Methods in Psychology - 4th American Edition @ KPU

Related