Validity This refers to the extent to which the test measures what it claims to measure If an IQ test actually measures intelligence = valid However, many argue it is not; that it is an invalid measurement Reliability This refers to how controlled and consistent a study is A friend who is consistently late = reliable with lateness

Validity This refers to the extent to which the test measures what it claims to measure Face – does the test appear to test what it aims to test? (EG. Does IQ testing really measure intelligence?) Concurrent – does the test relate to an already existing measurement? Ecological – does the task/experiment reflect that of real life? Internal – does the test measure what is intended to or has other extraneous factors influencing? Population – Is the sample representative of the wider target population of the study Construct – does the test relate to underlying theoretical concepts? External – looks at factors outside of the study. Who is the study meant to b representative of? Can it be generalised?

Reliability This refers to how controlled and consistent a study is Inter-rater - two or more individuals have a high agreement on a score and therefore the measurement of behaviour is reliable External - the methods used to measure behaviour receive the same or similar results when replicated Internal - whether a procedure in a study can be replicated eg. Can the tools used to measure behaviour be used again?