What is the relationship between measurement reliability and measurement validity?

Reliability (or consistency) refers to the stability of a measurement scale, i.e. how far it will give the same results on separate occasions, and it can be assessed in different ways; stability, internal consistency and equiva- lence. Validity is the degree to which a scale measures what it is intended to measure.

What are the measures of reliability?

Here are the four most common ways of measuring reliability for any empirical method or metric: inter-rater reliability. test-retest reliability. parallel forms reliability.

How do you measure validity?

To evaluate criterion validity, you calculate the correlation between the results of your measurement and the results of the criterion measurement. If there is a high correlation, this gives a good indication that your test is measuring what it intends to measure.

What are the methods of establishing reliability?

Another method to establish reliability is alternate-forms or parallel-forms. Administrators will give a parallel test (second test) after they have administered the first test. This helps to check for errors amongst the test and deems it reliable or unreliable (Cohen & Swerdlik, 2010).

What are examples of reliability of a measurement?

For example, measurements of people’s height and weight are often extremely reliable. There are several general classes of reliability estimates: Inter-rater reliability assesses the degree of agreement between two or more raters in their appraisals. For example, a person gets a stomach ache and different doctors all give the same diagnosis.

Is a reliable test always valid?

“A valid test is always reliable but a reliable test is not necessarily valid”. In education, there seems to be a certain emphasis placed on reliability and validity in assessment.

Why is reliability important?

Reliability is highly important for psychological research. This is because it tests if the study fulfills its predicted aims and hypothesis and also ensures that the results are due to the study and not any possible extraneous variables.