Can a Test Be Valid but Not Reliable?

A measure can be reliable but not valid, if it is measuring something very consistently but is consistently measuring the wrong construct. Likewise, a measure can be valid but not reliable if it is measuring the right construct, but not doing so in a consistent manner.

Can a test be valid without reliability?

As you'd expect, a test cannot be valid unless it's reliable. However, a test can be reliable without being valid. ... If you're providing a personality test and get the same results from potential hires after testing them twice, you've got yourself a reliable test.

Can studies be valid but not reliable?

The extent to which the results really measure what they are supposed to measure. ... A reliable measurement is not always valid: the results might be reproducible, but they're not necessarily correct. A valid measurement is generally reliable: if a test produces accurate results, they should be reproducible.