PSYB01H3 Study Guide - Pearson Product-Moment Correlation Coefficient, Inter-Rater Reliability, Internal Consistency
Document Summary
Reliability refers to the consistency or stability of a measure of behaviour. A reliable measure does not fluctuate from one reading to the next; if the measure does fluctuate, there is error in the measurement device. Any measure that you can make can be thought of as comprising two components: true score, which is the real score on the variable, measurement error. An unreliable measure of intelligence contains considerable measurement error and so does not provide an accurate indication of an individual"s true intelligence. A reliable measure of intelligence one that contains little measurement error will yield an identical (or nearly identical) intelligence score each time the same individual is measured. The measurement error in an unreliable test is revealed in the greater variability of its results of the unreliable test. It is important to use a reliable measure since researchers only measure each person only once.