Canonical occupational knowledge comprises a societal account or expectation comprising particular sets of understandings, procedures and values. In contemporary times, this canonical domain of occupational knowledge is often that which is presented in the form of professional standards and prescriptions for developing those capacities (i.e. curriculum documents). These documents are used to evaluate the relative worth of that profession, the extent and kinds of preparation it deserves, and the kinds of qualities required from those who would practise it. These canonical accounts, consequently, have become artefacts used for the organisation, administration and appraisal of occupations. This includes decisions about the development of occupation-specific educational provisions, their enactment and means of evaluation and assessing student competence and for then to be licenced to practise. So, canonical occupational knowledge increasingly manifested as a set of ideals, goals and decision- making about their educational forms and outcomes and means for distributing access to them.

The actual circumstances in which occupations are practised, requirements for enacting the occupation and how its enactment will be judged differ from situation to situation because the requirements for effective practice are shaped by the circumstances in which they are practised. Occupational performance is, therefore, manifested in a particular set of circumstances and demands for performance. Consequently, whilst the canonical domain of occupations exists as a societal entity, it is abstracted from the actual circumstances of practice, which can only be understood situationally. So, there will be particular arrays of concepts, procedures and values required for the occupational practice in specific work or community settings. Situational requirements stand, therefore, as a particular manifestation of canonical occupational knowledge, but with particular kinds of emphases and requirements that cannot be understood at the societal level. That manifestation is in response to localised requirements including what constitutes effective performance and what kinds of routine and nonroutine problem-solving are the hallmarks of expertise.

Ultimately, occupational competence is something learnt and subsequently enacted and demonstrated by individuals. It is the particular combination of what individuals know (i.e. understandings), can do (i.e. procedural capacities) and value (i.e. dispositions) that comprises their personal domain of occupational knowledge. That domain is a product of what individuals have constructed through experiences across their life histories and will always be, by degree, person-dependent. What individuals construct from what they experience will not be a mere replica of the textbook read or procedures modelled by more experienced workers, which are then faithfully appropriated by learners. Instead, these domains are the inevitable legacy of their particular experiences and processes of experiencing, including the work-related activities they engage with and the kinds of interactions they have with others. So, this personal dimension of occupational domain-specific knowledge needs to be included in considerations of competent occupational performance and how it might be developed through educational provisions and workplace experiences.