ERIC Number: ED467809
Record Type: Non-Journal
Publication Date: 1999-Mar
Reference Count: N/A
The Influence of Speededness on Item-Parameter Estimation. Law School Admission Council Computerized Testing Report. LSAC Research Report Series.
Schnipke, Deborah L.
When running out of time on a multiple-choice test such as the Law School Admission Test (LSAT), some test takers are likely to respond rapidly to the remaining unanswered items in an attempt to get some items right by chance. Because these responses will tend to be incorrect, the presence of rapid-guessing behavior could cause these items to appear to be more difficult than they really are. Using simulated date, this study found that when rapid-guessing behavior is present, items appear more difficult and less discriminating than they really are. Using response times, an attempt was made to remove responses that appeared to be the result of rapid guessing behavior. A two-state mixture model was fit to the response time distribution of each item, and responses that were more likely to come from the rapid-guessing distribution (according to the model) were removed. After removing the fast responses (rapid guesses), the item parameters, item characteristic curves, and information functions were recovered more accurately. When test data are contaminated by speededness (rapid guesses), this study shows that response times, if available, can be used to identify and remove rapid guesses and thereby recover the true item parameters more accurately. (Contains 4 tables, 8 figures, and 12 references.) (Author/SLD)
Publication Type: Reports - Research
Education Level: N/A
Authoring Institution: Law School Admission Council, Princeton, NJ.
Identifiers - Assessments and Surveys: Law School Admission Test