An analysis of research in reliability and validity

Some examples of the methods to estimate reliability include test-retest reliabilityinternal consistency reliability, and parallel-test reliability. Each method comes at the problem of figuring out the source of error in the test somewhat differently. Item response theory[ edit ] It was well-known to classical test theorists that measurement precision is not uniform across the scale of measurement. Tests tend to distinguish better for test-takers with moderate trait levels and worse among high- and low-scoring test-takers.

An analysis of research in reliability and validity

Like external validityconstruct validity is related to generalizing. But, where external validity involves generalizing from your study context to other people, places or times, construct validity involves generalizing from your program or measures to the concept of your program or measures.

You might think of construct validity as a "labeling" issue. When you implement a program that you call a "Head Start" program, is your label an accurate one? When you measure what you term "self esteem" is that what you were really measuring? I would like to tell two major stories here.

The first is the more straightforward one. I'll discuss several ways of thinking about the idea of construct validityseveral metaphors that might provide you with a foundation in the richness of this idea. Then, I'll discuss the major construct validity threatsthe kinds of arguments your critics are likely to raise when you make a claim that your program or measure is valid.

In most research methods texts, construct validity is presented in the section on measurement. And, it is typically presented as one of many different types of validity e.

I don't see it that way at all. I see construct validity as the overarching quality with all of the other measurement validity labels falling beneath it. And, I don't see construct validity as limited only to measurement.

As I've already implied, I think it is as much a part of the independent variable -- the program or treatment -- as it is the dependent variable. So, I'll try to make some sense of the various measurement validity types and try to move you to think instead of the validity of any operationalization as falling within the general category of construct validity, with a variety of subcategories and subtypes.

The second story I want to tell is more historical in nature. They needed personality screening tests for prospective fighter pilots, personnel measures that would enable sensible assignment of people to job skills, psychophysical measures to test reaction times, and so on.

After the war, these psychologists needed to find gainful employment outside of the military context, and it's not surprising that many of them moved into testing and measurement in a civilian context. During the early s, the American Psychological Association began to become increasingly concerned with the quality or validity of all of the new measures that were being generated and decided to convene an effort to set standards for psychological measures.

The first formal articulation of the idea of construct validity came from this effort and was couched under the somewhat grandiose idea of the nomological network. The nomological network provided a theoretical basis for the idea of construct validity, but it didn't provide practicing researchers with a way to actually establish whether their measures had construct validity.Results.

The principal component analysis confirmed the presence of a two-component factor structure in the English version and a three-component factor structure in the French version with eigenvalues > English version of the ISI had an excellent internal consistency (α = ), while the French version had a good internal consistency (α = ).

Marketing Research. Managers need information in order to introduce products and services that create value in the mind of the customer. But the perception of value is a subjective one, and what customers value this year may be quite different from what they value next year. Reliability is an essential pre-requisite for validity.

An analysis of research in reliability and validity

It is possible to have a reliable measure that is not valid, however a valid measure must also be reliable. Below are some of the forms of reliability that the researcher will need to address.

Assessment methods and tests should have validity and reliability data and research to back up their claims that the test is a sound measure.. Reliability is a very important concept and works in tandem with Validity.

A guiding principle for psychology is that a test can be reliable but not valid for a particular purpose, however, a test cannot be valid if it is unreliable. Jun 11,  · I am Me.

In all the world, there is no one else exactly like me. Everything that comes out of me is authentically mine, because I alone chose it -- I own everything about me: my body, my feelings, my mouth, my voice, all my actions, whether they be to others or myself.

Internal validity dictates how an experimental design is structured and encompasses all of the steps of the scientific research method. Even if your results are great, sloppy and inconsistent design will compromise your integrity in the eyes of the scientific community. Internal validity and reliability are at the core of any experimental design.

Testing and Assessment - Reliability and Validity