Identify the two basic concerns with using a correlation to ...

[tichca]

Identify the two basic concerns with using a correlation to measure split-half reliability and explain how these concerns are addressed by Spearman-Brown, K-R 20, and Cronbach's alpha.
 
  What will be an ideal response?

Question 2

An advantage of the median over the mean is that the median is
 
  a. easier to calculate.
  b. more sensitive to each of the sample scores.
  c. a measure of dispersion.
  d. less influenced by extreme scores..

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Answer to Question 1

The two basic concerns with using a correlation to measure split-half reliability are (1) the correlation is based on scores from only half of the test items and therefore tends to underestimate the true reliability of the full test; and (2) many different correlations are possible depending on how you decide to split the test items in half. Spearman-Brown addresses the first problem by adjusting the correlation upward to correct for the underestimation. K-R 20 and Cronbach's alpha both compute a measure that estimates the average correlation that would be obtained from all of the possible ways to split the test items in half.

Answer to Question 2

D

[tichca]

Thank you

[cloud]

No problem