ERIC Number: ED331855
Record Type: RIE
Publication Date: 1991-Apr
Reference Count: 0
Reliability and Confidence Envelope Usage in Item Response Theory.
Schumacker, Randall E.; Harris, Mark J.
Designing a test using three-parameter item response theory (IRT) is discussed. A brief review of IRT is followed by a discussion of two types of test design: (1) selecting items using confidence envelopes (confidence envelope method); and (2) using item characteristic curves and their confidence intervals (test envelope method). The confidence envelope method and the test envelope method are evaluated based on their reliability coefficients, using a set of seven items. Results illustrate that the test envelope method, in which optimum ability levels are matched from an item bank, should result in a more reliable test. Six tables and three graphs illustrate the analysis. (SLD)
Publication Type: Reports - Evaluative; Speeches/Meeting Papers
Education Level: N/A
Authoring Institution: N/A
Identifiers: Confidence Envelopes; Confidence Intervals (Statistics); Item Characteristic Function
Note: Paper presented at the Annual Meeting of the American Educational Research Association (Chicago, IL, April 3-7, 1991).