EXPOSITORY TEACHING OF HIERARCHICAL SUBJECT MATTERS'
JOSEPH
M.
SCANDURA
University
of
Pennsylvania
Experiments in which two or more teaching methods are compared as to
effectiveness have been notorious for their inconclusiveness. In one study, method
A might result in superior learning whereas, in another study, method B might
prove to be best. More frequently, there are no significant differences at all.
In conducting
a
series of exploratory studies in the classroom, each comparing
one expository method with one discovery method, Scandura (196413) was able to
identify one of the major reasons why such comparisons have
not
been definitive.
Relatively minor within-method differences seemed to have a greater effect on the
experimental outcomes than differences in the methods (i.e., expository and dis-
covery) themselves.
Nonetheless, the situation did not appear hopeless. In each
of the experiments conducted, the major determining factor appeared to be the
timing
of
the information given. Good teachers, of course, have long observed that
when
information is given is just as important as
what
information is given. Never-
theless, most teachers and even college teachers of teachers, would be hard pressed
to explain the mechanism involved.
A
better understanding of the underlying causes and effect.s of timing might
well help
to
improve existing methods courses for teachers of mathematics and other
hierarchical subject matters and, in turn, teaching in the schools. Still, the number
of controlled studies which have dealt with this problem is small indeed. Those
which involve reading technical materials have been almost non-existent; yet, this
is precisely the way in which the learning of most hierarchical subject matter takes
place.2
Although
timing
may be crucial, it is not always possible to tap and make
effective use of learner feedback when teaching by expository methods or in pre-
paring expository material. Not only must the prerequisites to learning be identi-
fied, but techniques are needed to help insure the attainment of these prerequisite
abilities before higher order information is presented. In effect, timing must be
characterized
in terms of variables under the direct control
of
the teacher or writer.
The general purpose of this research was to identify factors affecting the learning
of hierarchically arranged expository material and to help determine the relative
strengths of these factors. Familiarity with the ideas denoted by the signs (i.e.,
symbols and icons) used to describe higher order material was given the major
emphasis. Towards these ends, four experiments were conducted. All of the in-
struction took place via carefully prepared text-like passages and practice exercises.
METHOD
To
minimize the contaminating influence of uncontrolled individual differences in related knowl-
edge, an artificial, hierarchically ordered subject matter
was
used in the first three experiments
(Scandura, 1964a).
Four
levels
of
this material were identified for experimental purposes. At
level
one
were
12
one-to-one correspondences between certain display properties and the symbols which
'The research
on
which this paper is based was supported by the
U.
S.
Office of Education (Project
S-097).
The four research reports on which this paper is based were published in
The
Journal
of
Ex
erimentul
Education
during the summer and fall of
1966
(see Scandura, 1966a, b, c; Scandura
&
Betr,
1966).
2This statement should not be taken
as
an endorsement for expository
(as
opposed to discovery)
learning but simply
&s
a matter of fact.