Beyond the techniques and tools themselves, KBT also encompasses the manner in which they are applied, and the education, training and organisational structure and infra-structure which support their use. Conventional software development technology deals with procedures or algorithms which access and maintain precisely structured data. Conventional systems analysis focusses on specific problems, building up an understanding by accumulating detailed information about all of the various cases that have to be dealt with. On the other hand, KBT places emphasis on 'knowledge', and the new breed of 'knowledge engineers' are concerned with descriptions of whole 'problem-domains'. Individual cases are used as tests of the 'knowledge-base' which the knowledge engineer develops.
Few authorities make clear precisely what they mean by the term 'knowledge'.
This representation can be used to express rules, which are firm statements of defined relationships between variables. These relationships are based on causal models, and are generally true, or at least firmly believed to be generally true. In addition, the representation can be used to express heuristics, or 'rules of thumb', which may be used as a guide, and are usually true, but which sometimes may not be. They are based on correlation or intuition, rather than on causal models. Heuristics represent 'surface knowledge' about the domain, whereas rules represent 'deep knowledge'.