What is Validation?

Test validity means a test measures what it was intended to measure. For example, if a test is developed to measure knowledge of mechanical maintenance employees at the journey-level, a valid test should accurately measure the required knowledge and skills for this position. A "validation study" is the process of measuring the validity of a test.

There are different types of validity, but the most important type of validity for an achievement or skill test is content validity. Content validity looks at the match between test questions and the content or subject area they are intended to assess. In order to assess validity of an off-the-shelf test, the job description would be reviewed and compared to the knowledge and areas that a test covers.

In layman's terms, if you need to hire an electrician, select a test that evaluates that ability. If you need to hire a plumber, find a test that tests knowledge and skill in the plumbing area. Remember, even if the plumbing test has been validated, it is NOT a valid test to use when hiring an electrician. Employers who choose to purchase tests online or off-the-shelf must go through the process of evaluating the test in relation to the description of the job being tested.

Do I Need a Custom Validation?

A custom validation requires a job analysis by a qualified consultant who works with job experts to design a test that meets their specific needs. Although custom validation is best, many employers feel that they can test using an off-the-shelf test that has been validated for someone else. This option is much less expensive, but because a job analysis has not been done it is up to the customer to evaluate the off-the-shelf test and determine if a test samples the job knowledge needed for the position.

Cut scores are not set for off-the-shelf tests. Cut scores are products of the validation procedure.

In general, when unions are involved or there is a larger possibility of a challenge, such as hiring for a large company, Ramsay Corporation recommends conducting a validation study. More information about why your company might want to validate a test can be found in the article Why Validate.

Are There Other Types of Validation?

As previously mentioned, content validation uses a defined procedure to ensure that a test accurately measures the skills that are required for the job being tested. More information about Ramsay Corporation's validation procedures can be found in the articles below:
- Description of Technical Test Validation Procedure
- Description of Basic Skills Test Validation Procedure

Criterion-related validation uses statistical analysis to measure a test's ability to predict an outcome. A person's test score is compared to their job performance. A high score on a test would predict a high job performance rating. Research shows that tests that have content validity usually have criterion-related validity. An example of methods used in a criterion-related validation study.

Construct validity measure a test's accuracy at predicting performance against other assessments of known validity.