Ascertainment

Ascertainment refers to the process of identifying, measuring, or determining something accurately in a study or investigation. It involves selecting specific items, participants, or data points and ensuring they are correctly recognized and recorded. In research, proper ascertainment ensures that the information collected truly represents what is being studied, reducing errors and bias. For example, in genetic studies, ascertainment might mean carefully identifying people with or without a certain trait. Overall, ascertainment is about accurately finding and defining what needs to be measured to obtain reliable and valid results.