The Effect of Misinformation,Partial Information,and Guessing on Expected Multiple-Choice Test Item Scores

Abstract

Six response/scoring methods for multiple-choice tests are analyzed with respect to expected item scores under various levels of information and mis information. It is shown that misinformation always and necessarily results in expected item scores lower than those associated with complete igno rance. Moreover, it is shown that some re sponse/scoring methods penalize all conditions of misinformation equally, and others have varying penalties according to the number of wrong choices the misinformed examinee has categorized with the correct choice. One method exacts the greatest pen alty when a specific wrong choice is believed cor rect ; two other methods provide the maximum pen alty when the examinee is confident only that the correct choice is incorrect. Partial information is shown to yield substantially different expected item scores from one method to another. Guessing is an alyzed under the assumption that examinees guess whenever it is advantageous to do so under the scoring method used and that these conditions would be made clear to the examinee. Additional guessing is shown to have no effect on expected item scores in some cases, though in others it is shown to lower the expected item score. These out comes are discussed with respect to validity and reliability of resulting total scores and also with re spect to test content and examinee characteristics.