The reliability of a spelling test is .80.If the test is doubled in length, the reliability of the test will be approximately
A) .80.
B) .84.
C) .89.
D) .90.
E) 1.60.

Question

Quizplus · Accepted Answer

The reliability of a test can be increased by lengthening the test. This is described by the Spearman-Brown prediction formula, which, in simplified terms for doubling the length, suggests that reliability increases but doesn't double. The correct answer is approximately .89, indicating an increase in reliability but not to perfection or beyond.

The Reliability of a Spelling Test Is