Table 2

Glouberman and Zimmerman's model of simple, complicated and complex (adapted with permission from Liu et al10)

SimpleComplicatedComplex
Example task
 Non-clinicalBaking a cakeSending a rocket to the moonRaising a child
 ClinicalScreening for a urinary tract infectionScreening for gestational diabetesScreening for HIV
ProcessRecipe or set of instructions is necessaryFormulae are critical and necessary for successFormulae and recommendations are useful but limited in application
Expertise requiredNone, but previous experience can improve successHigh levels of expertise and specialised coordination of resources are necessaryExpertise can contribute but is not necessary or sufficient to ensure success
Uniqueness of outcomeA good recipe produces the same result every timeFollowing the formulae should ensure similar outcomesEach outcome is unique
Expected outcomeThe same result every timeHigh degree of certainty of outcome if formulae are followed correctlyOutcome is uncertain and cannot be reliably predicted beforehand