The Effect of Misinformation on Item Discrimination Indices and Estimation Priorities of Multiple-Choice Test Scores.

A specially designed answer format was used for three tests in a college level agriculture class of 19 students to record responses to three things about each item: (1) the student's choice of the best answer; (2) the degree of certainty with which the answer was chosen; and (3) all the answer choices which the student was certain were incorrect. Instances where the correct answer was identified as being incorrect were scored as instances of "misinformation." Other items that were not answered correctly were scored as instances of "ignorance." score was computed which was identified as being incorrect were scored as Another score was computed which was identified as "true ability." It was concluded that the additional effort required to obtain estimates of misinformation and ignorance was not justified by item discrimination indices, but was justified in providing appropriate remediation for students, depending on whether the examinee had ignorance or misinformation. (Author/CTM)