✰ An experiment in which the researcher examines the effects of a naturalistically-occurring treatment after that treatment has occurred rather than creating the treatment itself.
✰ Ex post facto study or after-the-fact research is a category of research design in which the investigation starts after the fact has occurred without interference from the researcher.
✰ It basically deals with non-manipulated variables of a phenomenon.
✰ An ex-post facto design or causal-comparative research is considered as quasi –experimental because the subjects are not randomly assigned- they are grouped based on a particular characteristic or trait. But the difference is, variables are manipulation in quasi experimental, but no variables are manipulated in ex-post facto research.
✰ It is used in social sciences and business organizations, field of behavioural sciences.
✰ In social science and business research we quite often use the term Ex post facto research for descriptive research studies.
✰ Ex post facto research projects are used for descriptive studies in which the researcher seeks to measure such items as, for example, frequency of shopping, preferences of people, or similar data.
✰ For example, if a child is delinquent (that is, one who indulges in criminal activities), then in order to find the basic reason behind such delinquency, the researcher would try to find out the various events that have occurred and the many possibilities that could have contributed to the concerned delinquent behavior. The expected possibilities may be lack of discipline at school/ family history/ peer effect/ neighborhood or socialisation.
