The purpose is to get a dependable, objective, and applicable
test.
Reliability means the stability of test scores.A reliable test
is consistent and dependable. It means if you give to the same
student or matched students on two different occasions, the test
should yield similar results.
By retesting the same individuals with the same test;Computing
reliability;Estimating the consistency with statistical techniques
such as a split-half method (Spearman Brown) and rational
equivalence by Kuder and Richardson (KR-20, KR-21)
Student-Related Reliability The most common issue is caused by
temporary illness, fatigue, anxiety, and other physical or
psychological factors. Test administration Reliability because of
street noise outside the building; students sitting next to the
windows could not hear the tape accurately;The amount of lighting
in different parts of the room, variations in temperature, and even
the condition of desks and chairs.
Validity is the degree to which a test measures.It measures what
it is supposed to measure.Types of Validity:Content
ValidityEmpirical ValidityFace Validity
It is designed to measure mastery of a specific skill or the
content of a particular course of study.
It is used to determine how test scores are related to some
independent such as marks given at the end of a course or
instructors or supervisors rating.The general types of empirical
validity:Predictive Validity is used to assess or to predict in the
case of placement test or aptitude test.Concurrent Validity means
that if the results are supported by other concurrent performance
beyond the assessment itself.
Face validity refers to the degree to which a test looks right
and appears to measure the knowledge or abilities.
Face validity will likely be high if learners encounter: a
well-constructed, expected format with familiar tasks; items that
are clear and uncomplicated;tasks that relate to their course work
(content validity).Content validity is a very important ingredient
in achieving face validity.
Construct validity is a major issue in validating large-scale
standardized tests of proficiency. Because such tests must for
economic reasons and adhere to the principle of practicality. The
example of construct validity is TOEFL.
An effective test is practical or usable. This means that it is
not excessively expensive, stays within appropriate time
constraints,Is relatively easy to administer,Has a
scoring/evaluation procedure that is specific and
time-efficient.
