two or more of the
foregoing lesson types.

In many inductive lessons the step of application really involves a
process of deduction. For example, after teaching the definition of a
noun by a process of induction as outlined above, we may, in the same
lesson, seek to have the pupil use his new knowledge in pointing out
particular nouns in a set of given sentences. Here, however, the pupil
is evidently called upon to discover the value of particular words by
the use of the newly learned general principle. When, therefore, he
discovers the grammatical value of the particular word "Provender" in
the sentence "Provender is dear," the pupil's process of learning can be
represented in the deductive form as follows:

All naming words are nouns.
_Provender_ is a naming word.
_Provender_ is a noun.

Although in these exercises the real aim is not to have the pupil learn
the value of the individual word, but to test his mastery of the general
principle, such application undoubtedly corresponds with the deductive
learning process previously outlined. Any inductive lesson, therefore,
which includes the above type of application may rightly be described as
an inductive-deductive lesson. A great many lessons in grammar and
arithmetic are of this type.

CHAPTER XVI

THE LESSON UNIT

=What Constitutes a Lesson Problem.=--The foregoing analysis and
description of the learning process has shown that the ordinary school
lesson is designed to lead the pupil to build up, or organize, a new
experience, or, as it is sometimes expressed, to gain control of a unit
of valuable knowledge, presented as a single problem. From what has been
learned concerning the relating activity of mind, however, it is evident
that the teacher may face a difficulty when he is called upon to decide
what extent of knowledge, or experience, is to be accepted as a
knowledge unit. It was noted, for example, that many topics regularly
treated in a single lesson fall into quite distinct sub-divisions, each
of which represents to a certain extent a separate group of related
ideas and, therefore, a single problem. On the other hand, many
different lesson experiences, or topics, although taught as separate
units, are seen to stand so closely related, that in the end they
naturally organize themselves into a larger single unit of knowledge,
representing a division, of the subject of study. From this it is
evident that situations may arise, as in