What does validity measure in research?

Validity in research fundamentally assesses how well a variable or measurement tool captures the concept it is intended to measure. It verifies whether the operational definitions and measurement techniques correspond accurately to the theoretical constructs they are designed to represent.

When a study demonstrates high validity, it indicates that the findings and conclusions drawn from the research can be trusted to accurately reflect the reality of the phenomenon under investigation. For instance, if a survey aims to measure depression and it uses a well-validated scale that accurately reflects symptoms and experiences of depression, then it can be said to have high validity.

In the context of research methodology, validity can come in several forms, including content validity, criterion-related validity, and construct validity. Each form provides insights into how well the measurement aligns with the intended variable or construct.

The other choices, while related to different aspects of research, do not capture the essence of validity. Reliability focuses on the consistency of a measurement tool, sample size pertains to the adequacy of the data collected for making general inferences, and simplicity of measurement relates more to ease of data collection rather than the degree of accurate representation of the variable being measured.