Reliabillity
consistency of findings
important for experiment to be classified as scientific, if we can trust findings
Internal validity
extent to which results from the study come directly from the manipulated independent variable
RPredictive validity
extent to which performance on measure can predict the future performance on a similar criteria
External validity
How well research findings stay can be generalised beyond study itself
Ecological validity
generalised to other situations
Population validity
generalise to other people
Objectivity
Impartial and judgement free