ERIC Number: ED389758
Record Type: Non-Journal
Publication Date: 1994-Nov
Reference Count: N/A
The Influence of the Presence of Deviant Item Score Patterns on the Power of a Person-Fit Statistic. Research Report 94-1.
Meijer, Rob R.
In studies investigating the power of person-fit statistics it is often assumed that the item parameters that are used to calculate the statistics can be estimated in a sample without aberrant persons. However, in practical test applications calibration samples most likely will contain aberrant persons. In the present study, the influence of the type and the number of aberrant persons in the calibration sample on the detection rate of the ZU3 statistic was investigated by means of simulated data. The ZU3 is a standardized version of the person-fit U3 statistic developed by H. Van der Flier (1980). An increase in the number of aberrant simulees resulted in a decrease in the power of ZU3. Furthermore, the type of aberrant behavior influenced the power of ZU3. The use of an iterative procedure to remove the aberrant persons from the dataset was investigated. Results suggested that this method can be used to improve the power of ZU3. (Contains 4 tables, 6 figures, and 17 references.) (Author/SLD)
Descriptors: Estimation (Mathematics), Evaluation Methods, Foreign Countries, Identification, Power (Statistics), Research Methodology, Scores, Simulation, Test Items
Bibliotheek, Faculty of Educational Science and Technology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.
Publication Type: Reports - Evaluative
Education Level: N/A
Authoring Institution: Twente Univ., Enschede (Netherlands). Faculty of Educational Science and Technology.