a complete description of a course of programmed instruction, containing precise statements concerning the size of lessons, the division of the learning material into units, the sequence in which readings from a text are to be presented, and the rules for transition from one unit to the next. Assimilation of the material by the students is tested by a series of questions. These questions must be answered either at the end of each unit of material or periodically during the process of study, and the transition to the next unit of material is made to depend on answering the questions correctly.
The most widely known programs are the linear and branching types. An instructional program is called linear when all students work on each unit of material in the same sequence; the answer may be given either by selecting one choice from a set of choices or by composing an independent answer. Independently composed answers produced during the process of instruction or memorization give better results than simple selection from two or several given choices, each of which appears very probable but may lead to unnecessary memorization of incorrect propositions. Linear instructional programs typically have short steps; that is, each new unit contains a small volume of material, which makes it easier for a student to compose or select a correct answer and therefore speeds up the learning process.
In the branching instructional program, the answer is used primarily to lead the student further along one of the program’s branches. Each answer is used to disclose the possibilities of the path chosen by the student and to determine what to do next. The branching program also allows incorrect answers that do not prevent reaching a correct result because they can be corrected before the student goes further.
A branching instructional program may be used to explain to a student what is wrong with his answers. Such programs make it possible to identify students who have not understood anything in the course and to return them to the very beginning of the explanation. They also permit a student with good preparation to go through a course faster than others, and they may be used to give the student himself an opportunity to decide how deeply he wishes to go into the material.
Other types of instructional program are also used. There are, for example, combined programs, in which linear programs at certain points pass into branching programs to permit the student who is progressing well to bypass a sequence necessary for students who have not completely mastered the material.