Learning Complex Concepts

1
Learning Complex Concepts
To decide if a stimulus is a member of a
conceptual category, you have to see if the
stimulus has certain attributes. These
attributes define the concept.
You then apply a conceptual rule that tells you
which attributes must be present or absent to say
that the stimulus is a positive instance of the
concept.
The more attributes a concept involves, the
greater is its logical complexity.
2
Learning Complex Concepts
Cognitive researchers have traditionally studied
more complex concepts than behavioral
researchers. In addition, cognitive researchers
have used a different kind of procedure for
presenting stimuli
Instead of presenting the same series of stimuli
across trials, as in the Kelleher experiment with
chimpanzees, a new stimulus is presented on every
trial.
To make the correct response to a stimulus, the
subjects must learn the concept they cant just
memorize the answers.
3
Learning Complex Concepts
Heres what its like. You will be shown a
series of faces. Each face consists of a set of
attributes
Rounded Eyebrows
Arched Eyebrows
Open Eyes
Closed Eyes
Upturned Mouth
Downturned Mouth
Your problem to decide whether each face youll
see is a positive instance of the concept.
4
Learning Complex Concepts
Only one attribute is relevant to solving the
problem.
Rounded Eyebrows
Arched Eyebrows
Open Eyes
Closed Eyes
Upturned Mouth
Downturned Mouth
When you see the face (stimulus), respond Yes
if you think its a positive instance or No if
you think its a negative instance.
5
Learning Complex Concepts
After you make your response, you will see the
answer.
Rounded Eyebrows
Arched Eyebrows
Open Eyes
Closed Eyes
Upturned Mouth
Downturned Mouth
From Matlin, M. (1983) Cognition. New York
Holt, Rinehart Winston.
6
Learning Complex Concepts
Yes
1
7
Learning Complex Concepts
Yes
2
8
Learning Complex Concepts
No
3
9
Learning Complex Concepts
No
4
10
Learning Complex Concepts
No
5
11
Learning Complex Concepts
Yes
6
12
Learning Complex Concepts
No
7
13
Learning Complex Concepts
Yes
8
14
Learning Complex Concepts
The concept is rounded eyebrows. You can
ignore all other attributes of the face and
respond correctly to each new stimulus by looking
only for the rounded eyebrows.
The first four faces provide enough information
to solve the problem. Heres how
Going from Face 1 to Face 2 This shows that
open and closed eyes are irrelevant since these
were the only changes and the answer was still
Yes.
15
Learning Complex Concepts
The concept is rounded eyebrows. You can
ignore all other attributes of the face and
respond correctly to each new stimulus by looking
only for the rounded eyebrows.
The first four faces provide enough information
to solve the problem. Heres how
Going from Face 2 to Face 3 Both the eyebrows
and the mouth have changed, so we cant yet tell
which change is responsible for the No answer.
....
16
Learning Complex Concepts
The concept is rounded eyebrows. You can
ignore all other attributes of the face and
respond correctly to each new stimulus by looking
only for the rounded eyebrows.
The first four faces provide enough information
to solve the problem. Heres how
Going from Face 3 to Face 4 This shows that an
upturned vs. downturned mouth is irrelevant. The
answer stayed No when the mouth changed. We
already knew that the change in eyes was
irrelevant. The arched eyebrows did not change
and the answer stayed No. So rounded eyebrows
are needed for a Yes answer.
17
Learning Complex Concepts
Concept learning is divided into two
subprocesses attribute learning and rule
learning.
Attribute learning is the process of discovering
the relevant attributes of a concept. Rule
learning is discovering whether the attributes
must be present or absent.
The demonstration with the faces would be an
example of __________learning.
attribute
Heres a demonstration of rule learning where you
know in advance which attributes of the stimulus
are relevant to the concept (Matlin, 1983).
18
Learning Complex Concepts
On each trial you will see a house with two
relevant attributes
a chimney
a window
An attribute may be present or absent.
What rule determines whether a house is a
positive instance of the conceptual category?
19
Learning Complex Concepts
Positive Instance?
YES
1
20
Learning Complex Concepts
Positive Instance?
YES
2
21
Learning Complex Concepts
Positive Instance?
NO
3
22
Learning Complex Concepts
Positive Instance?
YES
The rule is ...?
4
23
Learning Complex Concepts
If the house has a chimney, it must also have a
window. Any house without a chimney is also a
positive instance.
This is known as the conditional rule, or
implication the presence of one attribute
implies the presence of another.
In the next presentation we will look at rules at
three levels of logical complexity and see how
complexity relates to the difficulty of learning
the concept.