Reliability refers to the consistency of test results over time and across raters. There are several potential sources of error in test scores, including issues with the test-taker, test administration, test scoring, and test construction. Several methods can be used to estimate a test's reliability, including test-retest reliability, inter-rater reliability, parallel forms reliability, internal consistency reliability, split-half reliability, and the Kuder Richardson method. Ensuring high reliability is important so that tests produce consistent results.

2. What is Reliability?

Reliability refers to the consistency
of a measure. A test is considered
reliable when we get the same result
repeatedly. It is impossible to
calculate reliability exactly, but it
can be estimated in a number of a
different ways.

3. Errors of measurement
Test-Takers- this sources of errors
takes place into consideration what is
happening within the individual like
fatigue, hunger, headache, emotional
upset and anxiety growth.
 Test- Administration- it can be cause
by lighting of examination room, room
temperature, noise, sitting
arrangement, instruction, attitude of
test examiner.


4. Test- Scoring- factors that contribute
to error in scoring include miskey,
wrong answer to test items, mistake in
correcting answer, mistake in the use
of correcting pencil and subjective
scoring.
 Test Itself- the difficulty of the test,
may contain poorly constructed items
that gives clues, ambiguous items, very
easy items and very difficult.

Expert agree that the longer the test the
higher is its reliability.

5. Different Methods Of
Reliability
Test-Retest Reliability- the test is
administered twice at two different
points in time. It is best use for
things that are stable over time.
 Inter-rater Reliability- assess by
having two or more independent
judges score the test. The score has
been compared to determine the
consistency of the raters estimate.


6. Parallel Forms Reliability- gauged by
comparing two different test that were
created using the same content.
 Internal Consistency Reliability- use to
judge the consistency of results across
items on the same test. When we see a
question that seems very similar to
another test question. It may indicate
that two questions are being use the
gauged reliabity.


7. Split-half- give parallel form of test
with in crease time interval between
forms using Pearson R formula.
 Kuder Richardson- give the test
once then correlate the proportion
and percentage of the student
passing and not passing a given
items with the measure of internal
consistency.


8. Unida Christian Colleges
Thank you 