P.R. Liehr’s scientific contributions

The foundation of middle range theory reported during the past decade was described and analyzed. A CINAHL search revealed 22 middle range theories that met selected criteria. This foundation is a fi rm base for new millennium theorizing. Recommendations for future theorizing include: clear articulation of theory names and approaches for generating theories; clarifi cation of concept linkages with inclusion of diagrammed models; deliberate attention to research-practice connections of theories; creation of theories in concert with the disciplinary perspective; and, movement of middle range theories to the front lines of nursing research and practice for further analysis, critique, and development.