Numerous studies have demonstrated the validity of biographical data in psychological diagnosis, and several meta‐analyses have confirmed their effectiveness in specific applications. In contrast, the present meta‐analysis (based on 116 studies with 165 independent validities) addresses the recent discussion on methodological artifacts in the development and validation of biographical instruments. Threats to validity are identified in (a) general issues of research design and (b) specific techniques used to construct and validate biographical data. The effects on estimated mean validity of both methodological artifacts and situational moderator variables were compared, and it was demonstrated that they cannot be treated independently. The meta‐analysis also showed that a validity of .220 still remained after making corrections for all analysed artifacts, and that not all methodological criticisms were just