The main four types of reliability are:
- Inter-rater: it is the type of reliability test performed on
different people, however, the test remains the same for all these
participants.
- Test-Retest: it is the type of reliability test that is
performed on the same people but at different intervals.
- Parallel form: it is the type of reliability test that is
performed on a different set of people at the same time but these
tests are different from each other.
- Internal Consistency: it is the type of reliability test that
is performed with test questions being different but having the
same characteristics and context.
Both reliability and validity are somewhat inter-relted but have
a different concept altogther. Where reliability is to measure the
results of a test to ensure if they are consistent. On the other
hand validity is to understand and check the accuracy of these
tests.