Which type of validity focuses on agreements between two measures of the same ability?

The type of validity that considers the agreements between two measures of the same ability is known as concurrent validity. This type of validity assesses how well a new test correlates with an established measure of the same construct, indicating that both measures are accurately capturing the same underlying ability at the same time. For example, if you have a new psychological assessment tool, you would evaluate its concurrent validity by comparing its results with those from an already validated measure of the same psychological construct. High levels of agreement between the two measures provide evidence that the new test is a valid measure of that ability.

Predictive validity, in contrast, examines how well one measure can predict future performance on another measure, which is not the focus of this question. Content validity evaluates whether a test effectively covers the entire domain of the concept it aims to measure, while face validity is about the apparent relevance of the test items to the construct being measured. Therefore, the context of concurrent validity is specifically centered around the simultaneous agreement between two established measures of the same ability, which makes it the correct choice for this question.