- Slides: 16
VALIDITY by Barli Tambunan/69110054
Contents �Definition of Validity �Explanation �Conclusion
Definition of Validity
Validity is often assessed along with reliability - the extent to which a measurement gives consistent results.
� Validity is not a property of a test. Rather, it refers to the use of a test for a particular purpose. � To evaluate the utility and appropriateness of a test for a particular � If the use of a test is to be defensible for a particular purposes, sufficient evidence must be put forward to defend the use of the test for that purpose. � Evaluating test validity is not a static, one-time event; it is a continuous process. (Sireci, 1998 a, for an additional historical perspective on validity)
� Measures, samples and designs don't 'have' validity -- only propositions can be said to be valid. � Technically, it is a proposition, inference or conclusion that can 'have' validity. � Test validity identified the test with the degree of correlation between the test and a criterion. � Validation endeavor requires integration of construct theory, subjective analysis of test content, and empirical analysis of item and test score data (Lissitz and Samuelsen : 2007).
Content Validity � Content is a non-statistical type of validity that involves “the systematic examination of the test content to determine whether it covers a representative sample of the behavior domain to be measured” (Anastasi & Urbina, 1997 p. 114). � Content validity evidence involves the degree to which the content of the test matches a content domain associated with the construct.
Criterion – related Validity � Criterion validity evidence involves the correlation between the test and a criterion variable (or variables) taken as representative of the construct. In other words, it compares the test with other measures or outcomes (the criteria) already held to be valid. � If the test data and criterion data are collected at the same time, this is referred to as concurrent validity evidence. If the test data are collected first in order to predict criterion data collected at a later point in time, then this is referred to as predictive validity evidence.
Face Validity � Face validity is an estimate of whether a test appears to measure a certain criterion; it does not guarantee that the test actually measures phenomena in that domain. Indeed, when a test is subject to faking (malingering), low face validity might make the test more valid. � Face validity is very closely related to content validity. While content validity depends on a theoretical basis for assuming if a test is assessing all domains of a certain criterion meanwhile face validity relates to whether a test appears to be a good measure or not. This judgment is made on the "face" of the test, thus it can also be judged by the amateur.
How to Make Tests More Valid
The two realms that are involved in research
� The first, on the top, is the land of theory. It is what goes on inside our heads as researchers. It is where we keep our theories about how the world operates. � The second, on the bottom, is the land of observations.
Conclusion � One aspect of the validity of a study is statistical conclusion validity - the degree to which conclusions reached about relationships between variables are justified. This involves ensuring adequate sampling procedures, appropriate statistical tests, and reliable measurement procedures. Conclusion validity is only concerned with whethere is any kind of relationship at all between the variables being studied; it may only be a correlation.
� An inquiry into the validity of a test should first concern itself with the characteristics of the test that can be studied in relative isolation from other tests, and from the intent or purpose of the testing. (Sireci : p 37) � The theory of validity, and the many lists of specific threats, provide a useful scheme for assessing the quality of research conclusions. The theory is general in scope and applicability, well-articulated in its philosophical suppositions, and virtually impossible to explain adequately in a few minutes. As a framework for judging the quality of evaluations it is indispensable and well worth understanding.