The Picture Exchange Communication System (PECS) is an augmentative /alternative communication strategy for those who display little or no speech. The rationale for PECS and its training sequence is described. Each phase of training is associated with specific behavior analytic teaching strategies. Skinner's analysis of Verbal Behavior forms the basis for teaching particular skills at specific points in the training sequence and also provide guidelines for how best to design the teaching strategies. Common problems and potential solutions are offered for various levels of training. The relationship between PECS and the co-development of speech, as well as its impact upon other behaviors (e.g., behavior management concerns, social orientation, etc.) is briefly reviewed. **********
