When translated literally, ex post facto means ‘from what is done afterwards’. In the context of social and educational research the phrase means ‘after the fact’ or ‘retrospectively’ and refers to those studies which investigate possible cause-and-effect relationships by observing an existing condition or state of affairs and searching back in time for plausible causal factors. In effect, researchers ask themselves what factors seem to be associated with certain occurrences, or conditions, or aspects of behaviour. Ex post facto research, then, is a method of teasing out possible antecedents of events that have happened and cannot, therefore, be controlled, engineered or manipulated by the investigator (Cooper and Schindler 2001: 136). Researchers can report only what has happened or what is happening, by trying to hold factors constant by careful attention to the sampling.