ERIC Number: ED333015
Record Type: Non-Journal
Publication Date: 1991-Apr
Reference Count: N/A
Concurrent Adaptive Measurement of Multiple Abilities.
Ackerman, Terry A.; Davey, Tim C.
An adaptive test can usually match or exceed the measurement precision of conventional tests several times its length. This increased efficiency is not without costs, however, as the models underlying adaptive testing make strong assumptions about examinees and items. Most troublesome is the assumption that item pools are unidimensional. Truly unidimensional item pools are the exception rather than the rule, so procedures have been established for handling multidimensional pools. One option is to insure that every adaptive test measures the same composite of the multiple abilities represented in the item pool. However, this approach forfeits the multidimensional structure of the item pool. The alternative is to retain this structure by splitting the item pool into more unidimensional subsets and administering each separately. This approach, however, increases testing time. A third approach is proposed--concurrent adaptive measurement. In this approach collateral information--information that an item provides about a secondary ability--is used to update ability estimates obtained from adaptive tests administered in separate content areas. A study is reviewed, which evaluated the effectiveness of the concurrent adaptive measurement procedure using unidimensional estimates of two two-dimensional item pools of 200 items each. The results indicate that both bias and the standard error of the estimated ability decrease when collateral information is used. As the correlation between the latent skills increases, the standard error drops slightly. Six tables and four figures are included. (SLD)
Publication Type: Reports - Evaluative; Speeches/Meeting Papers
Education Level: N/A
Authoring Institution: N/A