The purpose of an investigation is to determine something; to find out what, why, and who. A researcher searches for something new, an advance in the field of study. A doctor determines a diagnosis, a form of investigation. A police officer, at the scene of a motor vehicle traffic crash, or a burglary, or a suspicious death similarly investigates in order to determine what happened, what laws were violated and who was responsible. All these have one thing in common—the necessity to gather facts (data), assess their relevance and integrate them into a sensible and reasonable and correct conclusion. This requires expertise.
