1 Defining a functional status clarification first defining a set of mutually exclusive and collectively exhaustive levels of functioning.
2 Classifying symptoms and problems. Kaplan and Anderson say that in addition to Function level clarifications, an exhaustive list of symptoms and problems was generated as "subjective complaints are an important component of a general health measure because they relate dysfunction to a specific problem", and that 21 CPX complexes represented "all the possible symptomatic complaints that might inhibit function".
3 Using preference weights to integrate the 3 functional sub scales and the Symptom/Problem complexes into a single numerical expression. Human judgement studies were used to determine weights for the different states, and random samples of citizens from the community were used to evaluate the relative desirability of a good number of health conditions. A mathematical model was developed to describe the consumer decision process, these weights then being used to describe the relative desirability of all the function states on a scale from zero (for death) to 1.0 (for asymptomatic optimum function).