The definitions below are based in on nursing definitions that my wife turned me on to in:
Benner, P (1984)
From Novice to Expert: Excellence and Power in Clinical Nursing Practice, Menlo Park CA, Addison-Wesley
There was a time when a certified diver was competent, now they are almost always a novice, rarely a beginner. There was a time when an instructor was an expert, today one is lucky to find one that is proficient.
Novice: Diving knowledge is minimal and solely 'textbook.' It does not connect decisions with actions and ignores the context in which the action will be taken. The available suite of skills rigidly adhere to learned rules, other responses are not readily available. The possible use of knowledge for planning is without situational awareness and lacks discretionary judgment. The diver has available only rational decision making tools, nothing is intuitive or holistic. Individual actions are seen (and taken) in isolation with no conception of, or capability to deal with, complexity. Performance is unlikely to be satisfactory unless closely supervised.
Beginner: The diver has developed a working knowledge of key aspects of tasks and appreciates that complex diving situations exist. Since situational awareness is limited, all attributes and aspects tend to be treated separately and given equal importance. Though the begins to use global characteristics of situations that are recognized from limited prior experience, problems are primarily solved by using rote guidelines for action that are based on a situational attributes. The diver is starting to make rudimentary attempts to decide on appropriate actions in context, but is limited to applying actions as a series of steps, and thus can not be expected to successfully resolve complex situations. Though supervision is needed for the accomplishment of the overall task, straightforward tasks likely to be completed to an acceptable standard and the beginner is able to achieve some steps using own judgment.
Competent: The diver now has a good working, as well as some background, knowledge of diving and as a result can deal with knowledge in context. Recognition of relevance is now present. Actions are seen, at least partly, in terms of longer-term goals. The dive is able to cope with simple multiple, simultaneous, competing inputs. Sees actions (at least partially) in terms of longer-term goals. The diver performs best with standardized and routine procedures, but is able to achieve most tasks using own judgment and can engage in conscious and deliberate planning. Skills are fit for the purpose intended, though may lack refinement.
Proficient: Posses a depth of understanding of the disciplines that make up diving as well and those specific to diving so that the diver can make a holistic assessment in context rather than just an analytic one. The diver can deal with complex situations holistically, and decision-making is more confident. Performing to a fully acceptable standard is routine, as is seeing what is most important in a situation. Deviations from the normal pattern are quickly perceived. Decision-making is less labored. Maxims are used for guidance, but there is understanding that conclusions will (and should) vary according to the situation. The diver sees the overall 'picture' and how individual actions fit within it. The diver is able to take full responsibility for own work (and that of others where applicable).
Expert: The diver is capable of making correct decisions on an intuitive basis (e.g., no longer needs to rely on rules, guidelines or maxims) and posses authoritative knowledge of disciplines that make up diving that leads to a deep tacit understanding and a holistic and intuitive grasp of situations. In complex situations, the diver moves easily between intuitive and analytical approaches, using analytic approaches used only in completely novel situations or when problems occur. The diver sees the overall 'picture' and simultaneously grasps alternative approaches. Is comfortable taking responsibility for going beyond existing standards and creating original interpretations using a vision of what is possible. Excellence is achieved with relative ease.
