Definitions:
Accuracy: The extent to which observed values, the data produced by measuring an event, match the true state, or true values, of the event as it exists in nature (Cooper, Heron, & Heward, 2007).
Reliability: Refers to the consistency of measurement, specifically, the extent to which repeated measurement of the same event yields the same values (Cooper, Heron, & Heward, 2007).