Characteristics of a Good Test: Validity

       I.            INTRODUCTION

In conducting language test, it should be followed by a good quality of the test itself. There are two characteristics of good test: validity and reliability. Validity is the one that will be discussed in this summary. 

    II.            SUMMARY OF CONTENT

A valid test is test which is measured accurately what it is intended to measure. The concept of validity reveals a number of aspects, each of which deserves our attention. A test is said to have content validity if its content constitutes a representative sample of the language skills, structures, etc. with which it is meant to be concerned. The test of grammar, for example, would have content validity if it included a proper sample of the relevant structures. Just what are the relevant structures will depend, of course, upon the purpose of the test. In order to judge whether or not a test has content validity, we need a specification of the skills or structures etc. that is meant to cover. Such a specification should be made at a very early stage in test construction.

There are two importances in validating the content of test. First, the greater a test’s content validity, the more likely it is to be an accurate measure of what it is supposed to measure.  Secondly, such a test is likely to have harmful backwash effect. Areas which are likely to become areas ignored in teaching and learning.

The effectiveness of a content validity strategy can be enhanced by making sure that the experts are truly experts in the appropriate field and that they have adequate and appropriate tools in the form of rating scales so that their judgments can be sound and focused.

There are essentially two kinds of criterion-related validity: concurrent validity and predictive validity. Concurrent validity is established when the test and the criterion are administered at about the same time. The second kind of criterion-related validity is predictive validity. This concerns the degree to which a test can predict candidates’ future performance. An example would be how well a proficiency test could predict a student’s ability to cope with a graduate course at a British University. The criterion measure here might be an assessment of the student’s English as perceived by his or her supervisor at the university, or it could be the outcome of the course.

The test would have construct validity only if we were able to demonstrate that we were indeed measuring just that ability. Construct validity is the most important form of validity because it asks the fundamental validity question: What this test really measuring? Constructs underlie the variables that researcher’s measure. You cannot see a construct; you can only observe its effect. “Why does the person act this way and that person a different way? Because one is intelligent and one is not – or one is dishonest and the other is not.” We cannot prove that constructs exist, just as we cannot perform brain surgery on a person to “see” his or her intelligence, anxiety, or honesty.

A test is said to have face validity if it looks as if it measures what it is supposed to measure, for example, a test which pretended to measure  pronunciation ability but which did not  require the candidate to speak (and there have been more) might be thought to lack face validity. A test which does not face validity may not be accepted by candidates, teachers, education authorities or employers. It may simply not be used; and if it is used, the candidates’ reaction to it may mean that they do not perform on it in a way that truly reflects their ability.

There are some uses of validating test. First, every effort should be made in constructing tests to ensure content validity. Where possible, the tests should be validated empirically against some criterion. Particularly where it is intended to use indirect testing, reference should be made to the research literature to confirm that measurement of the relevant underlying constructs has been demonstrated using the testing techniques that are to be used.

      

 III.            CONCLUSION

Much has been written about characteristic of language tests. Discussions have centered on the tests which have validity characteristics. Validity becomes important part of constructing a good test. Those are the conclusion of the summary related to the topic.

REFERENCES

Hughes, Arthur. (1983). Testing for Language Teachers. UK: Cambridge University Press.