A Researcher Constructs a Five-Item Measure of Attitudes Toward National

Multiple Choice

A researcher constructs a five-item measure of attitudes toward national health insurance. The average intercorrelations among the items is r_ii = .40. Using the Spearman-Brown formula, he finds that R^SB = .77. What is the reliability of the scale as a whole?

A) .77
B) .50
C) .40
D) Cannot be determined without knowing the sample size.