kascetesting.blogg.se - Test validity and reliability

TEST VALIDITY AND RELIABILITY HOW TO

If there were no random errors of measurement, the individual would get the same test score, the individual's "true" score, each time. These factors are sources of chance or random measurement error in the assessment process. Differences in training, experience, and frame of reference among raters can produce different test scores for the test taker. In certain tests, scoring is determined by a rater's judgments of the test taker's performance or responses. Because the forms are not exactly the same, a test taker might do better on one form than on another. These forms are designed to have similar measurement characteristics, but they contain different items. Different forms of a test are known as parallel forms or alternate forms. Items differ on each form, but each form is supposed to measure the same thing. Many tests have more than one version or form. Differences in the testing environment, such as room temperature, lighting, noise, or even the test administrator, can influence an individual's test performance. For example, differing levels of anxiety, fatigue, or motivation may affect the applicant's test results. Test performance can be influenced by a person's psychological or physical state at the time of testing.

Test taker's temporary psychological or physical state.

How do we account for an individual who does not get exactly the same test score every time he or she takes the test? Some possible reasons are the following:

If a person takes the test again, will he or she get a similar test score, or a much different score? A test that yields similar scores for a person who repeats the test is said to measure a characteristic reliably. Test reliability Reliability refers to how dependably or consistently a test measures a characteristic. For example, an arithmetic test may help you to select qualified workers for a job that requires knowledge of arithmetic operations.The degree to which a test has these qualities is indicated by two technical properties: reliability and validity.

By using the test, more effective employment decisions can be made about individuals.

In other words, the test measures one or more characteristics that are important to the job. For example, a test of mental ability does in fact measure mental ability, and not some other characteristic.

The test measures what it claims to measure.

This means that if a person were to take the test again, the person would get a similar test score.

The test measures what it claims to measure consistently or reliably.

What makes a good test?Īn employment test is considered "good" if the following can be said about it: Use assessment tools that are appropriate for the target population. Use only assessment procedures and instruments that have been demonstrated to be valid for the specific purpose for which they are being used. Use only reliable assessment instruments and procedures.

TEST VALIDITY AND RELIABILITY HOW TO

How to interpret validity information from test manuals and independent reviews.

Using validity evidence from outside studies.

Methods for conducting validation studies.

Interpretation of reliability information from test manuals and reviews.

These explanations will help you to understand reliability and validity information reported in test manuals and reviews and use that information to evaluate the suitability of a test for your use. This chapter provides a simplified explanation of these two complex ideas. You should examine these features when evaluating the suitability of the test for your use. These are the two most important features of a test. Test reliability and validity are two technical properties of a test that indicate the quality and usefulness of the test.

Time and Attendance/Workforce ManagementĬhapter 3: Understanding Test Quality-Concepts of Reliability and Validity.