a. Validity 1. Definition Validity
To make a test, Validity is one of criteria that is important. Because from validity, the teacher will know the quality of test. The purpose to know the
quality, the teacher can improve the test if the test has bad validity. James Dean Brown defined validity is a criteria of good test that has function
to help the teacher to make decision about the students’ ability. Teacher used
some kinds of test to know the students ability, there are admissions, placement, achievement, and diagnostic test.
7
Beside, definition from Brown, Douglas gave more explanation about Validity, they are:
a. Validity refers to the result of a test or evaluation instrument for a given
group of individuals, not to the instruments itself. Test makers sometimes speak the validity of the test, for the sake of the convenience, but it is more
approppriate to speak of the validity of the test results, or more special, of the validity of the interpretation to be made from the result.
b. Validity is matter of degree. It doesn’t exist in an all or none basis
consequently, test makers should avoid thinking of evaluation results as valid or invalid. Valid is best considered in term of categories that specify
degree, such as high validity, moderate validity, and low validity. c.
Validity is always specific to some particular use. It should be never considered a general quality.
8
Similar to Peter W. Airisian and Michael K.Russel, Validity defines decisions that are made from assessment information, not the assessment approach itself. It
is not approppriate to say the assessment information is valid unless the decisions, purpose, and groups for which it is valid are identified. Assessment information
7
James Dean Brown, Testing in Language Programs, New York: McGraw-Hill, 2005,p.220
8
Loc,Cit p. 66-67.
that is valid for one decision or group of students is not necessary valid for other decision group.
9
The writer conluded that validity is important. Because without validity, we never know whether the test measure what should be measured. From validity,
know the test have been valid or not.
2. The Purpose of Validity
Ahmand and Glock divide three purpose validity. Each purpose has fuction. There are three purpose:
10
First, to know how good students understanding the meterial in learning process. It means that if test taker can know how well the students accept or
understand what they have taught, they can give test that measured the
undertanding. For example, if we see the reading skill, we can measure the students with reading aloud.
Second, to analyze the students’ readiness before they get new material. It means that the test is to see how far the students master or know the knowledge
before they came to class. For example the aptitude test. The aptitude test could be given to completing junior high school to predict their academic success in senior
high school. Third, To predict what students strength related to the undertanding the
material . For example, a teacher might give a memory test to a class to make inferences about each pupil’s scholactic aptitude.
9
Peter W.Airasian and Michael K.Russel, Classroom Assessment, New York, McGraw-Hill, 2008.p.16
10
J. Stanley Ahmann and Marvin D. Glock, Evaluating Pupil Growth, Boston: Allyn and Bacon, 1971p.278
Kategori