Validity is the extent to which a concept, conclusion, test or measurement accurately provides what it’s supposed to; or, corresponds accurately to the real world. Reliability is the degree to which the result of a measurement, calculation, or specification obtained by administering the same test twice over a period of time to a group of individuals can be depended on to produce stable and consistent results. Tests that are valid are also reliable. Evaluation techniques are valid as they measure what a student has learnt in a particular period/term and therefore they are also reliable However, tests that are reliable aren’t always valid, e.g., if a clock is five minutes slow it would be reliable, measuring the same duration correctly every time; but, it would not be valid as it would not be showing the right time.