What does validity assess in research instruments?

Validity in research instruments is critical as it determines whether an instrument measures what it is intended to measure. This means that if a test or survey is designed to assess a specific construct, such as depression, validity checks if the items on the instrument accurately capture the essence of depression rather than something else, like anxiety or general wellbeing.

Establishing validity can involve different types, such as construct validity, content validity, and criterion-related validity. Each type helps ensure that the resulting data from the instrument genuinely reflects the theoretical concepts being studied, leading to credible conclusions and effective interventions.

In contrast, the consistency of application relates to reliability, which is about the instrument producing stable and consistent measurements over time. Sample size considerations pertain to the generalizability of findings, while statistical significance deals with the likelihood that results are not due to chance. While these factors are important in research, they do not pertain directly to what validity assesses.