Can I Count On You: Test Reliability
You may have already read Three Things To Know BEFORE Choosing a Test for Hiring or Who Built My Personality Test. Today we’ll talk about the importance of Reliability in your selection test.
Research shows that personality tests most effectively predict job performance when they reliably measure traits. A test is considered reliable when it has the following 3 conditions:
- Traits are stable across time. If a personality trait measured today is expected to predict work behaviors in the future, it is important that an applicant’s level of the trait does not change over time. Reliable tests measure traits, which are stable across time, not states, which are more likely to change based on a situation.
- Test scores do not change. If an applicant’s level of a trait is stable across time, then they should receive the same score on that trait each time they take the test. This is known as test-retest reliability and can be measured by test developers.
- Applicants respond consistently to items within a scale. An applicant who is high on the measured trait should respond in a similar way to all items measuring that trait; in other words choose “5” on a 1 to 5 rating scale for most items. Similarly, an applicant who is low on the trait should respond “1” to all or most items. If an applicant responds high to some items and low to others this can be problematic. This is referred to as internal consistency reliability.
Up next, we will look at the importance of being able to prove the test predicts job-relevant outcomes.