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Note: Glossary links are in boldface.
To
better understand why Engelmann's Direct Instruction is so effective
and so maligned by the educational establishment, we will explore
further his theory of instruction. In the book Theory of
instruction: Principles and applications, Engelmann and co-author
Douglas Carnine laid out a dramatic and contentious plan for the
development of effective instruction
(Engelmann & Carnine, 1991). What follows is a brief
introduction to some of the basic concepts of Engelmann's approach. One
longstanding controversy in developmental and educational psychology
concerns the relative contributions of "nature" vs.
"nurture." Both perspectives acknowledge that children are
biological organisms who interact with their environment -- at issue
are the relative contributions of the child's biological nature or
the nurturing role of the environment. Those from the nature camp
assert that development and learning are, primarily, a result of
biological unfolding of structure and function, and that educational
methods should acknowledge the nature of the child and the inevitable
stages of development
(Piaget,
1980). Those from the nurture camp assert that development and
learning are a result of the interaction of the biological organism
with the environment, that the environment plays a primary role, and
that education itself is an environmental intervention to expedite
development (e.g.,
Bijou & Baer,
1978). Engelmann and Carnine leave no doubt where they stand on
the nature vs. nurture controversy when it comes to intellectual
development, learning and instructional design. They come down
clearly on the side of nurture, asserting that the environment is the
primary variable accounting for learning. The characteristics of the
learner are recognized as important, but since instruction
necessarily involves making changes in the learner's environment,
environmental events are the focus of their instructional analysis.
Engelmann
and Carnine argue that a theory of instruction ought to be based upon
a scientific analysis. They recognize that it is impossible to study
scientifically the relationship between the environment and the
learner without holding one of these factors constant and
systematically varying the other. And since the learner cannot be
held constant, it is the environment (the instruction) that must be
carefully controlled. In effect, the instruction must be held
constant in order to learn about the learner. When carefully
controlled instruction is systematically presented to learners, the
differences that learners bring to the situation can be measured and
evaluated. The focus on carefully specified and controlled
instruction is fundamental to Engelmann's scientific analysis of
learning and development, and it is a cornerstone of his theory of
instructional design and practices.
Imagine
that one could design instruction in such a way that it would
communicate to the learner one and only one interpretation. There
would be no misunderstandings, no confusion and no misdirection.
Concepts would be learned perfectly. If this were true, then if one
wanted to teach the concept "vudged," one would be sure
that the instruction was going to allow the learner to identify cases
where "vudged" was appropriate and cases where "vudged"
was not. Vudged? What is vudged? Let's try to learn it. First
it will be my turn to communicate the concept of "vudged."
I'll show you some examples and some non-examples. Then there is a
little test to see if you've learned the concept. Relax. Remember
I'm going to communicate the concept so that there is no possibility
of misinterpretation. Did
you learn vudged? If you labeled the first, third and fourth items in
the second row as vudged, then you got it. If we were to state
"vudged" as a rule, it might be something like "not
aligned horizontally," or more simply "tilted." Did
you come up with something like that as your worked your way through
the examples and non-examples? The
instruction presented you with examples of vudged and non-examples of
vudged, isolated the feature that made things vudged or not vudged,
and then tested to see if the instruction generalized to other
stimuli. Logically, the instruction had to succeed. When instruction
conveys the concept so accurately, Engelmann calls it logically
faultless. Such
faultless communication leads
learners precisely to a single interpretation of the instruction, and
ideally that same instructional communication would work for
all learners. When instruction is faultless, it provides us a way of
studying the learner. We can present faultless instruction to a
number of learners and observe the effect of the instruction on their
learning. Because the instruction is the same for all learners, we
can rule out instructional factors accounting for observed
differences in learning. Thus, each learner's response to the
instruction provides precise information about the learner. This
analysis is similar to the logic of "standardized tests"
where the test and the testing conditions are held constant, and the
response of the examinees is allowed to show variation. However,
Engelmann's main interest is not in dividing students into categories
for sorting purposes. His main interest is in developing instruction
that will achieve faultless communication with all learners. Of
course, in the real world of teaching, even when the instruction is
logically faultless it doesn't always achieve the anticipated
results. When instruction that has been designed to be faultless
fails for a particular child, the teacher must resort to a remedial
(behavioral) analysis. That is, the teacher must assess the child's
behavior in relation to the particular instruction, and help the
child learn the missing skills. Since
faultless communication is the core of the logic of Direct
Instruction, allow us to restate the concept once again. What a
learner learns is a function of the communication received
(instruction) and characteristics of the learner that s/he brings to
the situation. If the instruction is designed in such a way that it
communicates a single intended interpretation to the learner (i.e.,
faultless instruction), then any misinterpretation by the learner
must be a function of learner characteristics. If logically
faultless instruction fails to achieve the intended communication,
then it cannot be a fault of the instruction. Rather, a failure of
the instruction indicates that there is a problem with the behavior
of the learner, and remedial steps should be aimed at resolving the
learner's difficulties. The design of faultless instruction involves
a logical analysis of the stimuli presented to the learner rather
than a behavioral analysis of the learner's characteristics.
However, if faultless instruction fails, then the educator must turn
to a behavioral analysis of the learner to provide appropriate
remediation. Remember
that we call instruction faultless because it logically communicates
the intended concept. This is what Engelmann calls a
logical analysis. We can judge if a
communication is faultless through logical analysis without attending
to the effect of the instruction on learners. When we look at the
functional relationship between a learner's behavior and the
instruction, we are performing a
behavioral
analysis.
Engelmann
and Carnine summarized the steps as follows:
"1. Design
communications that are faultless using logical analysis of the
stimuli, not a behavioral analysis of the learner.
2. Predict that the
learner will learn the concept conveyed by the faultless
presentation. If the communication is logically flawless and if the
learner has the capacity to respond to the logic of the presentation,
the learner will learn the concept conveyed by the communication.
3. Present the
communication to the learner and observe whether the learner actually
learns the intended concept or whether the learner has trouble. This
information (derived from a behavioral analysis) shows the extent to
which the learner does or does not possess the mechanisms necessary
to respond to the faultless presentation of the concept.
4. Design instruction
for the unsuccessful learner that will modify the learner's capacity
to respond to the faultless presentation. This instruction is not
based on a logical analysis of the communication, but on a
behavior analysis of the learner."
(Engelmann & Carnine, 1991, p. 3)
At
first reading, the above notion of faultless instruction and the
logical analysis might sound like Engelmann is blaming the learner
for failures to learn. That is not the case. Engelmann ultimately
takes responsibility for the learning of the student. When faultless
instruction fails the teacher must move to an analysis of behavior to
take steps that will correct deficiencies in the learner's cognitive
repertoire. Where Engelmann and Carnine differ from some popular
approaches to instructional design is that they do not assume the
learner will learn regardless of the communication
(Lally & Price, 1997).
Theorists
often begin by laying a foundation of facts and assumptions. Facts
are statements that are universally accepted to be true, and
assumptions are statements that are required to be true for the
theory to make sense. Generally, theories with fewer assumptions are
preferred over theories that must make many assumptions. Theories
with fewer assumptions are considered to be more
parsimonious. The theory of instruction
posed by Engelmann and Carnine makes two simple assumptions about the
learning mechanism possessed
by learners.
"Any
sameness shared by all examples that are treated in the same way
describes a generalization"
(Engelmann&
Carnine, 1991, p. 9). If a new example has the qualities
of all prior positive examples, then the learning mechanism will
classify the example as an instance of the concept. If the new
example does not have the same qualities as prior positive examples,
then the mechanism will classify the example as a non-example. These
rule-construction and generalization-testing processes are not viewed
as two distinct stages in learning. Rather, as each stimulus is
presented to the learner the proposed mechanism is busy constructing
and reconstructing the rules based upon the qualities of the
examples, and making generalizations on the basis of the samenesses
between past examples and the current stimulus.
Let's try teaching
a concept. Imagine that we want to teach a naïve learner the
concept of "green." We will assume that the child has
normal sensory equipment that is capable of responding to differences
in color and other physical aspects of visually presented examples
(Engelmann's first assumption) -- the child is not color blind. We
might start our teaching by presenting an example and saying to the
child, "This is green." The first example might be a solid
green rectangle, 4 cm on a side, drawn on a sheet of white paper and
presented to the learner with one side base facing the child. Notice
that the example has multiple qualities. It has the color quality
that we intend to communicate as "green." And the example
has other qualities too including size (4 cm), context (on white
paper) and orientation. At this point the naïve learner (or if
you prefer the learner's mechanism) might form any number of rules.
For example, the mechanism might pose the rule that "things
presented on white paper are green." Or, possibly that "objects
with four sides are green," or "objects with four vertices
are green." Notice that many interpretations are possible with
just one example. "It is logically impossible to present a
single example of a basic concept that shows only one concept"
(Engelmann & Carnine, 1991, p.
11). So far, the communication is not faultless!
Now
let's present another example to the learner and say, "This is
green." This time the example is a solid green circle, 4 cm in
diameter and drawn on a white sheet of paper. One
Identifiable Sameness. Notice that with the above two examples
there were multiple samenesses. We could continue to present example
after example to our learner. We might present pictures of various
green objects such as frogs and trees. But as long as there is more
than a single quality that is the same across all positive examples,
then the instruction would not be faultless. To eliminate such
miscommunication one must eliminate all irrelevant samenesses. "The
set of positive examples presented through the communication must
possess one and only one distinguishing quality"
(Engelmann & Carnine, 1991, p. 5).
What
could we do with our examples to eliminate irrelevant qualities? Our
second example might have been better if it had varied in many
respects from the first example. For example, instead of a 4 cm
circle drawn on paper we could have presented an irregular,
3-dimensional green object vastly different on a number of qualities
from the original green square. With carefully selected positive
examples it may be possible to leave the learner with a single
classification rule, but trying to teach with examples alone is not
efficient.
Signals.
Our examples above illustrate another element that is critical to
concept learning and generalization. Positive examples must be
treated in the same way during the communication, and negative
examples must be treated in a different way. In the two positive
examples the communication to the learner was "This is green."
In the negative example we used "not green." Engelmann
and Carnine refer to these labels as "signals." At the
minimum we need two signals to communicate a quality, one for
examples and one for non-examples. These signals are often verbal
such as "green" and "not green," but they need
not be. For example, it might be possible to simply sort examples
and non-examples into two piles, or to point to them in conspicuously
different ways. The advantage to using verbal signals is that most
learners can say the signals themselves, allowing an easy method of
assessing if the appropriate generalizations have occurred.
Restricting
the Range of a Concept. Most qualities are not absolute. For
example, "green" is not one particular wavelength of light
-- there is a range of acceptable wavelengths that are appropriately
classified as green. To communicate this range of a concept it is
essential that the selected examples and non-examples delimit the
range of the target quality. In our example we would want the
positive examples of green to vary within the normally acceptable
wavelength limits of green. We would want also to attend to
variations in brightness and saturation too so that the quality of
green would not be confused with these other physical aspects of
color.
Negative
examples are actually very important in defining the boundaries of a
concept. If we wanted the learner to respond differently to
green and colors of similar wavelengths, then we might want to
present those near non-examples (teal) and say, "Not green."
Non-examples provide a quick way to sharpen discriminations. Try
this one. What quality defines the concept "rectus?" 1 5 9 Have
you got it? Let's try a little test. Before reading further,
verbally label each of the items below as rectus or not rectus.
How
did the examples and non-examples work to teach you the concept? Can
you put the rule into words? If you labeled the band-aide and the
scales as rectus, and the sailboat as not rectus, then we are both on
the same wavelength. We think the sailboat is too vudged to be
rectus, don't you? The way that we would state the rule is this:
"Rectus: the item contains at least one horizontal or vertical
straight edge." Did you come up with a rule similar to that?
Notice
the specific sequence of items. In particular, note that the first
and second items differ only in terms of the orientation of the line.
The first one is an example of rectus and the second is not. By
juxtaposing these two items that differ in only one respect, and by
labeling them "rectus" and "not rectus," the
sequence has emphasized the relevance of the defining quality of the
concept. "The rule for accurately communicating differences
through examples is: To show difference, juxtapose examples that
are only minimally different and treat them differently"
(Engelmann & Carnine, 1991,
p. 12). The same rule applied to the fifth and sixth items in the
sequence.
Juxtaposition
can also be used to show sameness. "The rule: To show
sameness, juxtapose examples that are greatly different; treat each
example in the same way" "
(Engelmann & Carnine, 1991, p. 11).
Consider the ninth and tenth items.
Analyzing Whether
Communications are Faultless From
the Engelmann perspective, we judge if a communication is faultless
or not solely on the basis of the structure of the communication and
without regard to the behavior of the learner. This logical
perspective contrasts with other behavioral approaches to
instruction, where the environment is analyzed according to its
functional effects upon the individual
(e.g.,
Bijou & Baer, 1961;
Skinner, 1968).
Engelmann and Carnine specify the criteria for judging if
communication is faultless:
Before
we explore Engelmann's theory further, let's complete a short quiz on
the concepts we have covered so far. The quiz consists of five
questions. |
According to Engelmann and Carnine the learning mechanism generalizes
on the basis of samnesses. What qualities do the two examples have the same? With
these two examples we have several qualities that are the same: color
(green), width (4 cm), context (on white paper), symmetry, and
2-dimensionality, as well as all of the other features that the two
examples might share (e.g., on the table, in the room, etc.). These
two examples are still not faultless communication since there are
many possible rules and many qualities that might be the basis for
classification.
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