discriminating power of the overall test.
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When a larger proportion of students in the lower group got the item right more than those in the upper
group, it discriminates negatively. And since more students in the upper group than in the lower group got the item right, it is discriminating positively.
22
Item discriminating power can be obtained by subtracting the number of students in the lower group who got the item right U from the number of
students in the upper group who got the tem right L and dividing by the total number of students in one group included in the item analysis N.
It summarized in formula form, as below: DI = U - L
N Where:
DI = the index of discriminating power U = the number of pupils in the upper group who answered the item
correctly L = the number of pupils in the lower group who answered the item
correctly N = number of pupils in each of the groups
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The classifications of the index of discriminating power D are: DI = 0.70
– 1.00 = Excellent
0.40 – 0.70
= Good 0.20
– 0.40 = Satisfactory
≤ 0.20
= Poor Negative value on D= Very poor
24
21
William Wiersma, Educational Measurement and …, p. 245.
22
Gilbert Sax, Principles of Educational and …, p. 191.
23
Charles D. Hopkins Richard L. Antes, Classroom Measurement and Evaluation, Illinois: F.E. Peacock Publishers, Inc., 1990, p. 279.
24
Anas Sudijono, Pengantar Evaluasi Pendidikan, Jakarta: PT. Raja Grafindo Persada, 2006, p. 389.
3. Types of Test Item
In constructing the test items, the test maker may choose from a variety of item types. There are two types of test items: subjective test and
objective test.
a. Subjective test
Subjective test is attest which the examinee answers in his own words, and at appropriate length, all or some of a relatively small number of
questions. Typical key-words in the question set in examinations of this kind are: „discuss’, „compare’, „contrast’, „describe’, and the answer they
elicit may range from a single sentence to a dozen or more paragraphs. These answers are commonly called „essays’. Here are some subjectively
marked tests:
1 Short-Answer Items
The short answer or completion item is the only objective item type that requires the examinee to supply, rather than select, the
answer. Its make-up is similar to a well-stated multiple choice item without the alternatives. Thus, it consists of a question or incomplete
statement, to which the examinee responds by providing the appropriate words, numbers, or symbols.
2 Essay
Essay tests are inefficient for measuring knowledge outcomes but they provide a freedom of response that is needed in measuring certain
complex outcomes. These outcomes include the ability to create, to organize, to integrate, to express and similar behaviors that call for the
production and synthesis of ideas. The most noticeable characteristic of the essay test is the freedom
of response it provides. The student is asked a question that requires him to produce his own answer. He is relatively free to decide how to
approach the problem, what factual information to use, how to organize his reply, and what degree of emphasis to give each aspect of
his answer. Thus the essay question places a premium on the ability to produce, integrate, and express idea.
b. Objective test
Objective test is said to be one that may be scored by comparing examinee responses with an establishing set of acceptable responses of
scoring key. Objective test can be scored objectively. That is, equally competent scorers can score them independently and obtain the same
results. Objective test includes a variety of item types:
1 Multiple choice items
Multiple-choice refers to test items that require the students to select one or more responses from a set of two or more options These
items consists of a stem, which presents a problem situation, and several alternatives, which provide possible solutions to the problem.
The stem may be a question of an incomplete statement. The alternatives include the correct answer and several plausible wrong
answers, called distracters. The function of the latter is to distract those students who uncertain of the answer.
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Multiple choice items can measure a variety of learning outcomes, ranging from simple to complex, and it is easy to see why this item
type is regarded so highly and used so widely.
2 Matching Items
Another selected-response item, sometimes called an objective item, is the matching item. The format is not used as extensively as
true-false or multiple-choice items. But the matching item can be used
25
Norman E. Gronlund, Constructing Achievement..., p.38.
