Describe what reliability means in terms of research and why

Describe what reliability means in terms of research and why it is important. How does a researcher ensure that reliability is maintained in instruments and between raters?

Solution

Reliability refers to the consistency of a measure. A test is considered reliable if we get the same
result repeatedly. For example, if a test is designed to measure a trait (such as introversion), then
each time the test is administered to a subject, the results should be approximately the same.
Unfortunately, it is impossible to calculate reliability exactly, but it can be estimated in a number of
different ways.
In scientific research, accuracy in measurement is of great importance. Scientific research normally
measures physical attributes which can easily be assigned a precise value. Many times numerical
assessments of the mental attributes of human beings are accepted as readily as numerical
assessments of their physical attributes. Although we may understand that the values assigned to
mental attributes can never be completely precise, the imprecision is often looked upon as being toc
small to be of any practical concern. However, the magnitude of the imprecision is much greater in
the measurement of mental attributes than in that of physical attributes. This fact makes it very
important that the researcher in the social sciences and humanities determine the reliability of the
data gathering instrument to be used
It is important to note that just because a test has reliability it does not mean that it has validity.
Validity refers to whether or not a test really measures what it claims to measure. Think of reliability
as a measure of precision and validity as a measure of accuracy. In some cases, a test might be
reliable, but not valid. For example, imagine that job applicants are taking a test to determine if they
possess a particular personality trait. While the test might produce consistent results, it might not
actually be measuring the trait that it purports to measure.