Cognitive Continuum Theory can be used to explain why the relationship between research and practice is more problematic than is customarily assumed. The various possible sources of evidence for clinical decision making and the alternative approaches to such decision making can be located within the main modes of this continuum, each of which embodies a different balance of intuition and analysis. Decision analysis is the only technique that provides the analytical depth necessary to arrive at a decision that systematically identifies, structures and integrates all the relevant evidence on clinical parameters and patient preferences, within whatever mode that evidence is generated. The inappropriateness of using research criteria in action evaluations is pointed out. In order to illustrate the application of the Cognitive Continuum Theory and decision analysis to growth hormone (GH) therapy, and to stimulate discussion of this area, a primitive clinical decision analysis and prototype ‘clinical guidance tree’ for GH is presented here.