ERIC Number: ED185090
Record Type: Non-Journal
Publication Date: 1979-Dec
Reference Count: N/A
A Method for Investigating Item Bias Using Birnbaum's Three-Parameter Logistic Model. Iowa Testing Programs Occasional Papers Number 25.
It is proposed that statistical tests for item bias, when they are based on the three-parameter logistic item characteristic curve, should begin by testing for differences in the third parameter, the pseudo-chance level or "guessing" parameter. Other item-bias studies that have not considered the third parameter are discussed. Asymptotic significance tests for the three-item parameters are described. An experiment is described based on the 60-item Reading Comprehension Subtest of the Tests of Achievement and Proficiency, using the results for 400 black and 400 white ninth-grade students. None of the 60 items showed any indication of bias in the pseudo-chance level parameter so a weighted average parameter was computed and used in the remainder of the study. Comparisons of the difficulty and discrimination parameters did indicate some biased items. Some interpretation of the results are provided in relation to the content of the items. (Author/CTM)
Publication Type: Reports - Research
Education Level: N/A
Authoring Institution: Iowa Testing Programs, Iowa City.