Validity
Validity is the extent to which an instrument measures what one thinks it is measuring. Knowledge management testing instruments are designed for the purpose of appraising constructs such as knowledge acquisition, knowledge dissemination,
responding to knowledge related issues and the like.
Since there are no direct means of measuring these constructs, researchers must develop indirect means to measure complex attributes. These indirect means involve tests and scales consisting a number of items that are selected to serve as indicators of the complex constructs. If the tests and scales measure the constructs, then meaningful and useful inferences will be made from the test or scale scores. Hence, the test or scale is valid.
Validity is always specific to the particular purpose for which the instrument is being used.
A test that is valid in one situation and for one purpose may not be valid in a different situation or for a different purpose.
Validity can be classified into three types: content validity, criterion-related validity and construct validity.
Content Validity
This refers to the extent to which the samples of items or statement on a test are representative of some defined universe, or domain of content. The evidence for content validation is gathered by careful and critical examination by expert judges of the test’s content to determine if the contents are representative or those that constitute the content domain. For example, organizational performance scale should contain items that represent specifications of performance in terms of financial and non-financial outcomes.
Reliability
The reliability of a measuring instrument is the degree of consistency with which it measures whatever it is measuring.
Researchers are concerned about the consistency of their measuring devices when they attempt to measure such complex traits as performance, satisfaction, motivation, attitude and the like.
A test is reliable to the extent that the scores made by an individual remain nearly the same in repeated measurements.
Reliability can be estimated by correlating the scores obtained by the same individuals on different occasions or with different sets of equivalent items. These procedures require two administrators of a test, namely;
1)test-retest reliability; and
2)the equivalent-forms reliability procedures
References:
Aminah Ahmad & Maimunah Ismail (2006) Research method and design. Kuala Lumpur: Pusat Pendidikan Luar, University Putra Malaysia.
Ary D. Jacobs, L. C. & Razavieh, A. (1990). Introduction to research in education. (4th ed). Forth Worth: Rinehart and Winston, Inc.
Babbie, E. (2005). The practice of social research. Belmont: Wadsworth, Publishing Co.
Bryman, A., & Bell, E. (2007). Business research methods. (2nd ed). New York: Oxford University Press.
Mohd. Majid Konting (1990). Kaedah penyelidikan Pendidikan. Kuala Lumpur: Dewan Bahasa dan Pustaka.
Merriam, S. B. (1988). Case study research in education: a qualitative approach. San Francisco: Jossey-Bass.
