This document discusses reliability and validity, which are two important concepts for evaluating data collection methods in human services. Reliability refers to the consistency and dependability of measurements or assessments, and there are different types of reliability such as inter-rater reliability and test-retest reliability. Validity refers to whether a measurement or assessment accurately measures what it claims to measure. The document emphasizes that reliability and validity are crucial for human services to obtain accurate information through effective data collection methods when evaluating programs and services.