Reliabilitás

Reliabilitás is a key concept in statistics and research, referring to the consistency and dependability of a measurement tool or procedure. A reliable measurement will produce similar results under the same conditions, regardless of when or by whom the measurement is taken. It is distinct from validity, which concerns whether a tool measures what it is intended to measure. A tool can be reliable without being valid, but for a tool to be truly useful, it should ideally be both reliable and valid.

There are several ways to assess reliability. Test-retest reliability measures the consistency of results from one administration of a test to another. Inter-rater reliability assesses the degree to which different observers or raters agree on their measurements. Internal consistency reliability, often assessed using measures like Cronbach's alpha, examines how well different items within a test or scale measure the same underlying construct. For example, a thermometer that consistently shows the same temperature reading when measuring the same object multiple times demonstrates test-retest reliability. If two different people measuring the same blood pressure reading get very similar numbers, that indicates inter-rater reliability. A survey question that correlates highly with other questions designed to measure the same attitude suggests good internal consistency. Ensuring reliability is crucial for drawing accurate conclusions from data and for building confidence in research findings.