A unitary machine parsable language for use in data representation and problem solving in knowledge based services having a vocabulary of terms which derive from a natural human language to facilitate ease of comprehension by humans based upon a definition of the context of an item of information. A method of increasing the effectiveness of a knowledge based service consultation comprising splitting the consultation into at least a pre-consultation phase, a consultation phase and a post-consultation phase wherein information collected during earlier phases is electronically checked during the post-consultation phase.