One of the principal enterprises of publishers and equipment producers is the manufacture and sale of programs and teaching machines. Applications of these educational and training techniques are prevalent in education, special education, industry, and the military. Conflicting results have been obtained both within and among these areas. It is concluded that this lack of concordance is due both to the situation in which the technique is used and various programming technicalities. More control in future research concerning criterion tests, structuring of this situation, control groups, specification of objectives, motivational factors, and theoretical variables is recommended.