Background: While the quality of clinical research is often criticized, there is no underlying consensus on a definition of the term “quality” yet. Objectives: (1) To systematically survey definitions of quality in clinical research; and (2) to develop a conceptual framework of criteria[for full text, please go to the a.m. URL] ; SeriesInformation ; Klasse statt Masse – wider die wertlose Wissenschaft; 18. Jahrestagung des Deutschen Netzwerks Evidenzbasierte Medizin