An Alternative Type of Objective Exam John N. Aronson and Edward C. Krause SUNY-Albany, Albany, NY 12222 Subjective exams are frequently limited in scope t~ecause of the time factor. thev show unavoidable hiases in selection of material to be iesteh, and they are more diificult to grade than are "ohjecti\.e" exams. The simplest "ol)jectiv~."exam to grade, and prohably the most frequrntly usrd, is the standard multiple-rhoire exam. Each question is usually followed by four or five possible answers and the examinee is instructed to select the correct answer. Since several apparently reasonable answer choices are included to require a moderate level of discrimination by the examinee, this frequently introduces an element of eambline. " There results some uncertainty about how many correct choices are from gambles and how manv incorrect choices obscure some dearee - of knowledge. Coombs' has suggested an objective test that would yield a ereater variance in test scores on multide-choice examssimply cross out all alternative answers which the examinee considers to be incorrect. I t has two advantages over the traditionnl multiple-choice test. 'l'here is a more accurate discrimination between studentson the basis ith heir knowlrdge and the student is given credit for partial kn#,wledge,Le., what he kncgws ahout the incorrect choices. The need for measuring more of a student's knowledge and giving credit for partial knowledge has been pointed out previously by Hinckley and L a g o w ~ k iThey . ~ presented one way of "giving partial credit for answers which represent partial knowledge of the princi~ l e used."The s format we present here is s t r a i g h t f o m d and hoes not unequally weightanswers. Cwmbsl and associates3 discussed variations of this partial credit format. We have successfullv used our own modification and have recently developed a program by which this objective
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test can be computer scored and thoroughly analyzed. We usually have a five-answer format. Students are instructed to mark out up to four incorrect answers for each question. One answer is the most correct and should remain unmarked or no credit is given for that question. Thus, the only penalty deduction is within the same question and does not reduce the points gained on other questions. Exam scores are more diversely distributed than those from traditional multiple-choice exams. More information is aained about student knowledee 1)ecausewch qucsliun rwentially is a set of true-fdse queitions with higher weieht ei\.en 111 the winr of primarv nmcerii. There is nolost inform&ion, as tlqere is in the tiaditional multiple-choice format. his type of exam can be hand-graded with apunched out answer key. We have adapted, however, a computer-scoring program designed to score exams in which a variable number of correct answers exist. One option grades the exam in the manner previously described. A second option assigns one point for each correctly marked wrong answer and negative ooints, eclual to the number of possible resuonses minus one. fur inrurrecrly marked right answcrs.l 'l'here are additiuiial ststistics to help evaluace the test cluestions and the relatpd instruction. A more extensive description and further information regarding the program and test scoring method may be obtained from the authors.
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Coombs, C. H., EducationalandPsychologicalMeasurementXIII, 308-310 (1953). Hinckley, C. C. and Lagowski, J. J. CHEM. EDUC., 43, 575-578 91966). ~oombs.C. H.. Milholland,J. E.. and Womer, F. B., J. CHEM.EDUC., 16, 13-37 (1956).
Volume 59
Number 5
May 1982
381
