Examinations: Essay or objective-TWO
Views
provocative opinion
E o r ~ o n ' sNOTE: Thii month Provocative Opinion summariaes the views of two teachers who hold widely divergent views on what can he called classical examination methods. One of these authors is m Englishman, the other an American, but their views, while obviously conditioned by training, are shared or questioned by many colleagues regardless of national origin.
Favoring Essay Papers
Favoring Objective Exams
The purpose of an examination is to tell both student and teacher how much the former has absorbed and how apt he is at applying it. Although the relative importance of retention and applicability may vary, in general both should be tested. To be fair and reliable, an examination must cover the syllabus as widely as possible. The examination must have a good spread. Success should not depend on luck as to whether the part of the work the student has covered is the same as that on which the examiner has based his questions. I n the British system the essay paper is usual; in the U.S., the multiple-choice paper. I n this note I hope to assess the merits and demerits of each system.
The advantages listed for essay examinations are all well and good but I feel that they are far outweighed by the disadvantages. Students admittedly say they like essay examinations because it gives them the opportunity to write all they know but in the same breath they also admit that it gives them the opportunity to "talk-around" a question and throw in related but impertinent information and possibly gain unwarranted credit. Then too, if for some reason a student is unable to respond to a given essay question, he has lost a much larger percentage of the total credit for the examination than if he draws a complete blank on an objective type question. The time required to complete an essay examination is certainly longer than that for an objective examination, because the student must first sort out and organize the pertinent material, probably in an outline form, before he even begins to respond to the question. This takes time and varies from person to person. It is not difficult to visualize two individuals who "know" the same material but one is a better organizer, faster and neater writer so he gets more credit in the long run if a time limit is placed on the examination. Are we testing knowledge or writing ability? An objective type examination tests knowledge not writing ability, while a student still must have his material organized in a recallable fashion. We must remember that the student is enrolled in other courses and examinations that require longer than one or two hours to complete are really difficult to justify. If the time required to take an examination is important, then an essay examination becomes increasingly difficult to prepare and should probably be given a greater number of times during a term to obtain the greatest possible breadth of coverage. Objective type examinations on the other hand can cover a larger quantity of material with any given examination and therefore can be given less frequently. Essay examinations are somewhat limited in the manner in which questions are asked, "why, how, synthesize, show,. . . etc." Objective examinations may incorporate matching, multiple choice, completion, and True-False type questions. All of which may take a variety of forms even though some of us think only in terms of multiple choice questions when an objective examination is mentioned. The student is forced in most cases to instantly relate his knowledge to the questions asked.
The Multiple-Choice Paper
This involves in each question the choice of the most suitable of a number of suggested answers. The "Yes-No" question is multiple choice of two possible answers. Sometimes no suggestion may be made, but the candidate asked for his own short answer, Multiple-choice: The capital of Japan is: London, Chicago, Paris, l'okyo. Simple: What is the capital of Japan?
The multiple-choice paper has these advantages (1) Retention can be tested quickly. (2) Marking is quick and accurate. If desired the marking can he done by computer. (3) With the large number of questions, spread is easy to obtain.
Disadvantages and difficulties can be formidable (1) Although if care is taken to penalize guesswork, retention is accurately assessed, assessment of application is more difficult. With a correct answer there is no difficultv. But accuracy. (2) Equally, neither logical development of an argument nor critical use of data, can be tested. Such questions as (a) "Compare the relative merits of polyvinyl chloride and polyethylene piping for a town gas supply." (b) "In chemical properties vinyl.hromide is much more like hmmabenzene than ethyl bromide. Do you agree?" sre impossible in the multiple-choice paper.
A "Yes-No" paper must be scored "Number right minus number wrong." (Blank
(3) Guessing must he penelieed.
(Continued on p. 831, col. 1 ) 830
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Journal of Chemical Education
(Continued on p. 831, col. 2)
answers do not count.) Where the choice is of n possible answers, an approximation is
S
=
R - W/(n
- 1)
where S is the score; R, the number of right answers; and W, the number of wrong answers. (4) There may be more than one correct answer. Consider "A is a.point on a bicycle tire; B, a point halfway along a spoke. When the wheel is turned, which point moves more quickly?" (A, B, neither) Although A has the greater linear velocity, A and B have the same angular velocity. (5) I n a multiple-choice question, the correct answer is suggested. To remember a particular fact is much harder than to identify i t among a. number of others. (6) I t can be difficult to obtain wrong answers of equal plausibility. That one or two are obviously absurd reduces the odds against guesswork as dealt with in the formula above. (7) The position of the right answer must vary from question to question. Moreover, i t must be remembered that students shy a t choosing either the first or the last possibility. (8) Computer marking can lose the teacher valuable feedback as to where his students are going astray.
Although the short-question, multiple-choice examination, can be a valuable test of retention, there can be no test of ability to apply the facts. The Essay Examination
Commonly the "essay" paper consists of a number of questions (from 2 or 3 to 7 or 8, usually with a choice) to he done in, say, 3-hr. Some questions will be short essays; other questions will be problems or will involve in each case several short answers, e.g. (a) "Write notes on FOUR of the following:-"
(b) "Synthesize FIVE of the following:-"
A question may well consist of theory followed by application. The advantages of the essay paper is that it tests not only retention but also application. The student is allowed to come to grips with his subject, to choose his facts and handle them, and to show his maturity in the subject. Disadvantages and difficulties exist (1) The essay is harder to mark accurately than either the prohlem or the short answer. On the other hand. since a oaoer
some questions is balanced by severity in others. (2) Marking can be done neither by unskilled assistants nor by computer. (3) Because of difficulties of interpretation a student may argue over his mark. While prepared to listen to the case for a higher mark and if necessary to admit a mistake, the examiner must be firm that he is the final arbiter. (4) With the few questions involved, spread is more diffioult. Solving this difficulty is discussed later. (5) Examination stress may be greater. Several points, however, are significant (a) Some claim that the person who cracks under examination stress would not stand the stresses of his later professional life. (b) Teachers using continuous assessment on class tests in conjunction with terminal or sessional examinations agree that stress is of very little significance.
(Continued on p. 852, col. 1 )
If the recall is not immediate the student may procede with the examination and answer the questions that he can immediately and then return to those that require additional thought. Even though the student is not consciously thinking about the questions he has bypassed, sub-consciously he is trying to sort out the correct response and often times a correct response will unexpectedly come forth. I t is then much easier to apply that response to an objective type question than it is to fit it into the completed paragraph of an essay examination and maintain continuity and order. Without exception objective examinations may be more quickly, easily, accurately, uniformly, and reliably graded than an essay examination. The correct responses may be provided so little, if any, interpretation is required on the part of the grader. In contrast, an essay examination requires very careful consultation between the examiner and graders to assure uniformity and accuracy when grading the examination. An essay examination is subject to spells of leniency and severity from question to question and even from grader to grader. It is very diffioult to list or suggest all the ways students may attempt to answer a given question, and only an experienced teacher can grade questions exactly as he wishes. Objective examinations are not subject to periods of leniency and severity and a minimum of instruction is necessary if grading is relegated to graduate assistants. Ideally, all the examinations (objective) are graded immediately following the examination period by all the graders assembled in an area with the examiner. Then, if any questions arise, they may he answered on the spot by the individual who prepared the examination. This removes the burden of judgement decisions from the shoulders of inexperienced graders. To be sure multiple choice and True-False questions lend themselves to guessing and examiners should apply accepted scaling functions that lessen the advantage a student may gain by guessing. However, multiple choice responses may be so closely related that the student is unable to eliminate any of the answers without careful thought or work. Also, multiple choice questions may have more than one correct response among the possible answers that will help eliminate student guesses. True-False questions may also be altered to deter guessing by requiring the student to correct or make true statements of the questions he believes to be false. Matching type questions can be arranged to decrease guessing by always supplying more responses than questions asked and/or including more than one correct response for questions asked. Most universities and colleges still require a grade (either letter or percentage) for each course a student attempts so we must try to use the most reliable means of measurement as possible not only for the purpose of being fair to our students, but also ourselves as well. The objective examination is the more reliable examination. Results of examinations not only tell us how well our students have retained information and their ability to apply it, hut they should also tell areas of weakness of the students and the points that we have failed to make as clear as possible. I desire the greatest possible "feedbackn following an examination, because I feel that an important part of learning (education) stems (Continued on p. 85$, col. 2 ) Volume 46, Number 12, December 1969
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(o) In a recent paper on examinations the (British) National Union of Students quote with approval medical opinion depreciating the effects of examination stress.
Much is made of the alleged unreliahility of marking. Although examiners have blundered, often through lack of care, the occasional error does not invalidate the system. There is substantial evidence that in general careful examiners do mark accurately. Setting the Paper
I n this, four points must be watched (I ) Theory nrrd upplicntion mwt be reasonably balanced. ( 2 ) Thcrr must bc ndequatr ~prend. \Vith care, and r.peviully hv wiun the ..\i'rite rwtes od" or ' Swrhc.~irc" qneaiuns to c&er gaps Left after the main essays and problems have been set, it is possible to obtain adequate spread. (3) Psrts of a question should each he capable of being answered separately. Thus, if a. student in 8. practical examination is asked to clsssify an organic compound and then prepare two derivatives, a wrong classification can mean inability to p r e pare the derivatives and loss of these marks also. (4) The paper should be checked, e.g., by a colleague, for clarity and unambiguity. M. Dunstan (University of New South Wales, Ed. Kes. Bull. No. 1) comments Examiners.. .should realize that the production of good questions is one of the most exacting tasks in English composition, for few other wards are read with such critical attention to their expressed or implied meanings as those used in exrtminstion questions.
Marking
Several points must be made ( 1 ) The Marking Scheme. Especially where more than one examiner marks a particular question there must be, before marking begins, s clear idea of how the marks will be allocated within the question. The scheme must show clearly The essential points of the answer. (bl The relative weiehtines of these ~ o i n t s .
(a)
(2) The Borderline Case. When an answer scores about a passmark it is wise to decide qualitatively whether the answer is or is not worth a pass, and if necessary to adjust the mark accordingly. With the borderline paper, this adjustment is even more necessary. I t is a good idea also to ask a colleague to re-mark the borderline papers and to agree jointly on passes and failures.
If the above safeguards in setting and marking are taken, then the essay examinations can be quite reliable. Moreover, it can assess not only retention but also application.
P. A.
The
Ongley University of Aston
in Birmingham Gosto Green, Birmingham 4, England
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of Chemical Education
from the mistakes students make and that I make as well. Therefore, as rapid a return of the examination as possible following the examination period is necessary. The students do not like to be kept waiting and it is easier to discuss their errors then than after a week or more has gone by and they have more recent material on their minds. An objective examination permits an "item analysis" that readily reveals the areas students are having difficulty with and where a greater effort should be made by the student and instructor alike. It is more difficult to do this with an essay examination and effectively pinpoint specific weaknesses. Ongley quotes "Examiners . . . should realize that the production of good questions is one of the most exacting tasks in English composition, for few other words are read with such critical attention to their expressed or implied meanings as those used in examination questions." I agree wholeheartedly with that statement and I believe it becomes even more apparent that examination questions that lend themselves to misinterpretation and ambiguity are undesirable and are more apt to appear on essay examinations that include a few general broad questions than on objective examinations that include more specific questions requiring little if any interpretation. The one remaining point to consider when trying to decide upon an examination policy is the number of students to be examined. Can you imagine how long it would take to grade 200 essay examinations? I realize that not all teachers have that many students in class but the point is that a large number of us have that many and more so the time required for examination preparation, giving, and grading is an important factor in our time committment. Those of us who are fortunate enough to have graduate teaching assistants available to assist in the grading of examinations must also consider the value of their time when developing a testing program. An ohjective type examination is more suitable for large lecture sections. The preceding comments were made in reference only to "hourly" or final examinations. No attempt has been made to reflect upon the usefulness of essay or objective examinations in the total examination program established in a given chemistry course. My point of reference has been the general or beginning chemistry course. The type of examination used in any course must take into consideration several factors quite distinct and apart from the examination itself: the course level, maturity of the students involved, time available during the term, and certainly the philosophy and objectives of the course.
Clifford C. Houk Ohio Universily Athens, 45701
