Reliability analysis is a statistical method used to assess the consistency and dependability of a measurement tool or system. It helps determine how well a test or instrument produces stable and consistent results over time or across different conditions. Commonly used in fields like psychology, education, and engineering, reliability analysis ensures that the data collected is trustworthy. There are several types of reliability, including internal consistency, test-retest reliability, and inter-rater reliability. Each type evaluates different aspects of reliability, such as whether items on a test measure the same construct or if different observers agree on their assessments.