(2000.a) in Research Methodology stated that he idea behind internal consistency reliability is that items measuring the same phenomenon should produce similar results. This type of reliability test is useful for subjective measures where more than one rater can best describe the reliability of the test. The researcher asks more than one people to rate the reliability of his test. More than one tester or judge uses inter-rater reliability check to measure reliability. In social sciences, using parallel forms of same test is difficult and the issue of subjectivity arises. The researcher may also find it difficult to administer it to two similar populations. But the difficulty arises in formulating two tests that are similar in nature and measurement level. The researcher must be able to formulate two different tests that measure the same variables. Both forms of the test measure the same variables under study, but the format of the measure is different. It measures the reliability of the test by administering it in two different forms. But, this method of testing the reliability of the test is time-consuming, since the researcher has to wait for some time to re-administer the test. The results of the tests and the inferences drawn have to be applied to natural settings, they should be reliable. In natural sciences, the researcher conducts experiment more than one time to ascertain its reliability.

In social sciences, a test is administered more than one time over a period of time to check or retest its reliability. Test-retest reliability measures the reliability of the measure over a period of time. Types of reliability Test-retest reliability For example, rigor and control, sample representativeness, clarification, and justification are some ways to improve reliability in qualitative research. There are certain techniques that can help improve reliability in a qualitative research.

Reliability research methods