ERIC Number: ED374162
Record Type: Non-Journal
Publication Date: 1993
Reference Count: N/A
The Use of Confidence Intervals When Interpreting Test Scores. EREAPA Publication Series No. 93-4.
Wheeler, Patricia H.
A person's obtained score on a test provides an estimate of the individual's "true" score on that test. The obtained score is considered to have two parts, the true component and the error component. Classical test theory assumes that obtained scores for an individual over multiple administrations of the same test will lie symmetrically around the individual's true score. Confidence intervals can be used to determine the range within which the true score is apt to fall and to identify a second critical score when cut scores are used. To determine the upper and lower limits of a confidence interval, the standard error of measurement is multiplied by a number depending on the level of confidence needed for the situation. Multipliers come from a normal distribution based on the percentage of the total area under the normal curve between various standard deviations above and below the mean. How confidence intervals can be used to assess change, and when they should and should not be used, are discussed. (Contains 7 references.) (SLD)
Descriptors: Cutting Scores, Error of Measurement, Scores, Statistical Distributions, Test Interpretation, Test Results, Test Theory, True Scores
EREAPA Associates, 2840 Waverly Way, Livermore, CA 94550-1740 ($3).
Publication Type: Reports - Evaluative
Education Level: N/A
Authoring Institution: EREAPA Associates, Livermore, CA.