Abstract
This replication and critique addresses ongoing development and use of middle range theory since considering this body of nursing knowledge 18 years ago. Middle range theory is appreciated as essential to the structure of nursing knowledge. Nine middle range theories that demonstrate ongoing use by the theory authors are analyzed using the criteria of theory name, theory generation, disciplinary perspective, theory model, practice use and research use. Critique conclusions indicate the importance of staying with the theory over time, naming and development consistent with the disciplinary perspective, movement to an empirical level, and bringing middle range theory to the interdisciplinary table.