Validity: Validity refers to the extent to which a measure accurately measures what it intends to measure. Researchers need to ensure that their measures are valid to draw reliable conclusions from their data.
Reliability: Reliability refers to the consistency or stability of a measure over time or across different conditions. A reliable measure produces consistent results, allowing researchers to have confidence in their findings.
Self-report Measures: These are assessment tools that rely on individuals reporting their own thoughts, feelings, behaviors, etc. Examples include questionnaires and surveys where participants provide subjective information about themselves.