In Structural Learning Theory (SLT) all knowledge is represented in terms of rules. Structural learning rules include both declarative and procedural forms of representation. Specifically, rules have three components: domain, range, and operation. The domain consists of internal cognitive structures corresponding to the sum total of relevant environmental elements of a learning situation. Instructional application of these rules begins with an analysis of the objective in order to identify all of the component decisions and resultant actions required of a learner to satisfy the behavior specified. The greatest strength of the SLT is its ability to allow an instructor to quickly and accurately select content and sequencing requirements for training that will provide only that instruction needed by a learner. Indeed, the primary differences between an SLT-based lesson and other lessons are the precision of content selection and sequencing and their match to learner needs, and the validity of supporting test elements for the instruction.