EQUIVALENCE CLASS:
Complex behavior that consists of three defining relations of reflexivity, symmetry, and transitivity. Reflexivity refers to identity matching (e.g., Daddy is a specific man, 9 is a specific numeral); symmetry refers to functional reversibility (e.g., given a picture of a-dog, select the word dog, and given the word dog, the picture of the dog is selected); and, transitivity refers to the equivalence of three stimuli. 15
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EQUIVALENCE CLASS: A stimulus class (usually produced through conditional
discrimination in matching-to-sample) that includes all possible
emergent relations among its members. The properties of an
equivalence class are derived from the
logical relations of reflexivity, symmetry, and transitivity.
Reflexivity refers to the matching of a sample to itself, sometimes
called identity matching (AA, BB, CC, in these examples, each
letter pair represents a sample and its matching comparison
stimulus). Symmetry refers to the reversibility of a relation (if
AB, then BA). Transitivity refers to the transfer of the relation
to new combinations through shared membership (if AB and BC, then
AC). If these properties are characteristics of a matching
to-sample performance, then training AB and BC may produce AC, BA,
CA, and CB as emergent relations (reflexivity provides the three
other possible relations, AA, BB, and CC). Given AB and BC, for
example, the combination of symmetry and transitivity implies the
CA relation. The emergence of all possible stimulus relations after
only AB and BC are trained through contingencies is the criterion
for calling the three stimuli members of an equivalence class. The class can be extended by
training new stimulus relations (e.g., if CD is learned, then AD,
DA, BD, DB, and DC may be created as emergent relations). Stimuli
that are members of an equivalence
class are likely also to be functionally equivalent. It
remains to be seen whether the logical properties of these classes
are fully consistent with their behavioral ones. Cf. EQUIVALENCE
RELATION. |
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EQUIVALENCE RELATION: A term with various usages, including functional equivalence (the
relation between stimuli that have become members of a functional
class) as well as the mathematical relations that define an
equivalence class (especially the CA relation). The terminology of
equivalence relations has often been
interchanged with that of equivalencies classes, but the class and
relation terminologies should be distinguished because functionally
equivalent stimuli are not necessarily members of an equivalence
class. Cf. EQUIVALENCE CLASS. |
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ERROR:
In a simultaneous discrimination, a response to a stimulus not correlated with reinforcement; in a successive discrimination, a response in the presence of a stimulus correlated with extinction. Because of its colloquial origins, the term often assumes an evaluative as well as a descriptive function. CE CORRECTION PROCEDURE.
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ERRORLESS DISCRIMINATION PROCEDURE:
The use of a fading procedure to establish a discrimination, with no errors during the training.
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ERRORLESS LEARNING:
Acquiring particular discriminations by means of instruction designed to prevent errors. Sequences of artificial discriminative stimuli are arranged carefully and faded slowly and systematically so that control eventually shifts to the natural stimuli identified ultimately to evoke the response. 18
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ESCAPE:
See negative reinforcement.
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ESCAPE: The termination of an aversive stimulus by a response. A reduction
in the magnitude of an aversive stimulus by a response is sometimes
called partial or fractional escape.
Cf. REINFORCEMENT. |
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ESCAPE:
Any behavior that terminates a negative reinforcer.
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ESCAPE: The term escape describes a relation
between a performance and an aversive stimulus in which the
performance terminates the aversive stimulus. Escape is to be contrasted with avoidance, where
the aversive stimulus does not occur at all as long as the
avoidance performance continues to postpone it. |
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