[Who is dangerous? Problems of validity and reliability in assessment and documentation of socially aggressive behavior].

Records of violent behaviour and its sequels gain increasing interest as a matter of quality assurance. The paper presents scales and instruments applied in psychiatric institutions until now. While problems of reliability are solved sufficiently, there are major problems of validity in the measurement of violence. To be usable for quality management, a documentation has to provide a clear cut-off for the severity of violent incidents that should be reported. Otherwise uncomparable data and underreporting will result.