Data based on expert judgment involves information collected from well-informed and highly reputed experts in a given subject area. Experts may include activists, lawyers, or researchers. Data is usually gathered through interviews, but a self-administered questionnaire may also be used.
The sample of experts is usually small, but the data gathered can provide a variety of useful information. Data is relatively easy to gather, due to the small sample size and the general willingness of experts in the area to help with further studies. However, data may be biased or unrepresentative due to the small sample.
The Human Rights Measurement Initiative uses a calibrated survey of experts to assess civil and political rights across different countries.