This is a research process, which influence the validity and reliability of research findings Case studies, field studies, laboratory studies and other forms of studies have different levels of control. A case study describes what had happened in the past. The researcher has no control over the happenings. It is merely a guide to predict the future. In field study, the researcher has some cineol over the selection of research units, observations, interviews, data analysis and interpretation. Laboratory research has a higher degree of control over research units and analysis.