The simplest treatment alternative: the law of parsimony applied to choosing appropriate instructional control and errorless-learning procedures for the difficult-to-teach child.

A method for choosing effective teaching procedures for difficult-to-teach children is proposed. Assessment of child responses during teaching that involves gradually increasing environmental support in the learning setting is the basis for choice. The levels of environmental support in which child responses are assessed are (1) trial-and-error procedures; (2) increased environmental support involving analyses of reinforcement systems, incompatible responses, and prerequisite skills, as well as the most effective use of instructional control; and (3) errorless-learning procedures. Effects of instructions upon learning are discussed in terms of instructional detail and pacing, as well as with respect to the role of instructions in feedback and progressively delayed cue procedures. Stimulus shaping and stimulus fading are discussed in terms of the effectiveness of each for teaching children who have difficulty learning with more traditional procedures. The importance of the incorporation of criterion-related cues when utilizing stimulus shaping or fading is emphasized. It is proposed that an assessment of child responses should be made with respect to the three general levels of environmental support, as well as from sublevels within these, in order to choose the simplest but still effective alternative procedure for teaching difficult-to-teach children.