Summaries and Abstracts: Research onan Information Processing Theory ofVerbal Learning; Sim. of Human V. L. Bell.

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Summary of Research on an Information Processing

Theory of Verbal Learning, 1961-62.

Edward A. Feigenbaum

The research summarized in this report is concerned with the con-

struction of a theory of information processing activity underlying

human verbal learning behavior. The method employed is that of computer

simulation (Newell and Simon, 1961). The particular model under dev-

elopment is the Elementary Perceiver and Memorizer, described below.

Summary of Past and Present Research on EPAM

The Elementary Perceiver and Memorizer (EPAM) is a simulation of

human verbal learning behavior. EPAM simulates the information processes

by which humans discriminate and associate symbols in one or more sense

modes .EPAM is a computer program written in the list-processing language

IPL 5. Its behavior has been explored under a variety of experimental

conditions in some 100 runs on an IBM 704 and an IBM 7090. In the experi-

mental procedure, EPAM qua subject is put through certain verbal learning

experiments by an Experimenter program, which simulates the experimenter,

the apparatus, and the stimulus environment.

The EPAM programs are precise statements of hypotheses about information

processing in human learning. As with other simulations, the computer runs

with EPAM (i.e., the means by which the consequences of the model are

worked out for specific experimental conditions) enable us to test the

accuracy and consistency of the model in explaining the phenomena of

verbal learning.

Summary of Research on an Information Processing

Theory of Verbal Learning, 1961-62.

Edward A. Feigenbaum

The research summarized in this report is concerned with the con-

struction of a theory of information processing activity underlying

human verbal learning behavior. The method employed is that of computer

simulation (Newell and Simon, 1961). The particular model under dev-

elopment is the Elementary Perceiver and Memcrizer, described below.

Summary of Past and Present Research on EPAM

The Elementary Perceiver and Memorizer (EPAM) is a simulation of

human verba! learning behavior. EPAM simulates the information processes

by which humans discriminate and associate symbols in one or more MAM

modes.

EPA' computer program writ*. i list-processing language

IPL 5. Its tnhftTatOi has been explored under a variety of experimental

conditions in some 100 runs on an lIS*. 704 and an IBM 7090. In the experi-

mental procedure, EPAM qua subject is put through certain verbal learning

experiments by an Experimenter program, which simulates the experi.--'enter,

the apparatus, and the stimulus environment.The EPAM programs are precise statements of hypotheses about information

processing in human learning. As with other simulations, trie computer runs

with EPAM (i.e., the means by which the consequences of the model are

worked out for specific experimental conditions) enable us to test the

accuracy and consistency of the model in explaining the phenomena of

verbal learning.

EPAM I, an early model, dealtlji with the organization of the verbal

learning task by the learner (Feigenbaum and Simon, 196.5.,

EPAM 11, a later modal, contains a full complement of processes

for discrimination and association learning (Feigenbaum, 1961). The

behavior of EPAM II in serial-learning and paired-associates learning of

n nsense syllables ("classical** verbal learning experiments) exhibits a

variety of phenomena present in human behavior in the same experiments

(Feigenbaum sad Simon, 1961b).

KPAM 111. the latest model, generalizes the earlier models to deal

with tl -3 learning of stimuli of arbitrary complexity and the pair-wise

association of stimuli in any number of associative contexts. EPAM 111

embodies roecJianisms by means of wMc'h earlier learning can be brought to

bear in a useful way on current learning. Attempts are presently being

made to simulate behavior in experiments on the learning of meaningful

stimulus items (Feigenbaum and Simon, 1962).

Review of Recent Research

In the pr.st year, research on the EPAM theory has proceeded on three

fronts, corresponding roughly to the three versions of the EPAM model

just described.

The most important phase has been the formulation and programming of

EPAM 111, a generalization of the earlier versions, and an attempt to

correct some of their deficiencies. A statement of the goals and direction

of this phase of the research is appended. The EPAM 111 model is currently

being programmed. Experimentation with the model will be carried out in

the summer of 1962.

Empirical explorations of the earlier models have continued. Studies

EPAM I, an early model, dealt^ with the organization of the verbal

learning task by the learner (Feigenbaum and Simon, 1965.

EPAM 11, a later model, contains a full complement of processes

for discrimination and association learning (Feigenbaum, 1961). The

behavior of EPAM II in serial-learning and paired-associates learning of

n nsense syllables ("classical" verbal learning experiments) exhibits i

variety of phenomena present in human behavior in the same experiments

(Feigenbaum and Simon, 1961b).

EPAM 111, the latest model, generalizes the earlier models to deal

with the learning of stimuli of arbitrary complexity and the pair-wise

association of stimuli in any number of associative contexts. EPAM 111

embodies mechanisms by means of which earlier learning can be brought to

bear in a useful way on current learning. Attempts are presently being

made to simulate behavior in experiments on the learning of meaningful

stimulus items (Feigenbaum and Simon, 1962).

Review of Recent Research

In the past year, research on the EPAM theory has proceeded on three

fronts, corresponding roughly to the three versions of the EPAM model

just described.

The most important phase has been the formulation and programming of

EPAM 111, a generalization of the earlier versions, and an attempt to

correct some of their deficiencies. A statement of the goals and direction

of this phase of the research is appended. The EPAM 111 model is currently

being programmed. Experimentation with the model will be carried out in

the summer of 1962.

Empirical explorations of the earlier models have continued. Studies

of retroactive inhibition with varying degrees of intra-list similarity

of nonsense syllable materials were made. These EPAM experiments can

be summarized roughly as follows: the lower the intra-list similarity

of items in the first list, and the higher the intra-list similarity of

items in the interpolated list, the greater will be the retroactive inhi-

bition ovserved in the rete-st trial. Experiments on proactive inhibition

showed that the EPAM II model is incapable of exhibiting proactive in-

hibition, though there are "proactive" effects relating to rate o"

learning. A third series on transfer phenomena in the learning of pairs

of familiarized nonsense syllables is currently in progress, and results

are not yet available.

In parallel with this experimentation, further refinement of the

EPAM II model has taken place. In particular, new executive processes—

tiie high-le\'el learning "strategies" of EPAM—have been formulated and

programmed. Those new processes, representing important ai

"

>lifications,

have aided net cnly in the manipulation of the theory, but al'M in the

communication to others of the basic information processing postulates of

the theory.

A study of the possible implications of the EPAM theory for the con-

troversy on all-or-none vs incremental learning has been initiated. The

EPAM position is basically the following: that the discussion in this

controversy has been largely misguided by a focus on repetitions (exposures

per se) rather than on processing time available to subjects in the experi-

ments. Learning is incremental with respect to the acquisition of elements

of thc stimuli and the association cues. Learning is ;.11-or-none with

of retroactive inhibition with varying degrees of intra-list similarity

of nonsense syllable materials were made. These EPAM exper-iments can

be summarized roughly as follows: the lower the intra-list similarity

of items in the first list, and the higher the intra-list similarity of

items in the interpolated list, the greater will be the retroactive inhi-

bition ovserved in the retest trial. Experiments on proactive inhibition

showed that the EPAM II model is incapable of exhibiting proactive in-

hibition, though there are "proactive" effects relating to rate of

learning. A third series on transfer phenomena in the learning of pairs

of familiarized nonsense syllables is currently in progress, and results

are not yet available.

In parallel with this experimentation, further refinement of the

EPAM II model has taken place. In particular, new executive processes—

the high-level learning "strategies" of EPAM—have been formulated and

programmed. These new processes, representing important simplifications,

have aided not only in the manipulation of the theory, but also in the

communication to others of the basic information processing postulates of

the theory.

A study of tiie possible implications of the EPAM theory for the con-

troversy on all-or-none vs incremental learning has been initiated. The

EPAM position is basically the following: that the discussion in this

controversy has been largely misguided by a focus on repeat ions (exposures

per se) rather than on processing time available to subjects in the experi-

ments. Learning is incremental with respect to the acquisition of elements

of the stimuli and the association cues. Learning is all-or-none with

respect to the strategy employed by the subject tin focusing his attentionon one pair of items rather than on another. The EPAM I model successfully

simulated the experiments by Rock which initiated the discussion. It

remains to be seen vrtiether or not the results of tiie subsequent experi-

ments on all-or-none learning can be simulated with EPAM.

In an attempt to improve on the tools available for research insimulation of cognitive processes, work Is under way on the development

of more powerful information processing languages for Computers. Progress

on simulation of cognitive processes in general, and on EPAM

is directly related to the facility with which information processing

hypotinrsM a:, be expressed in a precise (and intelligible) fora computer, the power of the best ... u , for this Jtre»ea«fch presently

available, Information Processing Language V (Newell, et al., 1961), isbarely adequate. Our present effort is directed toward the formulation

of higher-level languages oriented toward problems in modeling human§mental processes.

References

1. Feigenbaum, E. A. An information processing theory of verbal learning.

The RAND Corp. Paper P-1817 (Oct. 1959).

2. Feigenbaun, E. A. Tiie simulation of verbal learning behavior. Proc.

Western Joint Comput. Conf. 19 (1961), 121-132.

3. Feigenbaum, E. A., and Simon, II „A. Performance of a reading task by an

elementary perceiving and memorizing program. The RAND Corp. Paper

P-235S (July 1961).

4. Feigenbaum, E. A., and Simon, H. A. Forgetting in an associationmemory. Preprints of tiie 16th Nat. Conf. ACM 16 (1961), 202-205.

respect to the strategy employed by the subject to focusing his attention

on one pair of items rather than en another. The EPAM I model successfully

simulated the experiments by Rock which initiated the discussion. It

remains to be seen whether or not the results of the subsequent experi-

ments cm all-or-none learning can be simulated with EPAM.

In an attempt to improve on the tools available for research in

simulation of cognitive processes, work is under way on the development

of more powerful information processing languages for Computers. Progress

cm simulation of cognitive processes in general, and on EPAM HI particular,

is directly related to the facility with which Information processing

hypotheses can be expressed in ■ precise (and intelligible) language for

a computer. The power of the best language for tills research presently

available, Information Processing Language V (Newell, et al., 1961), is

barely adequate. Our present effort is directed toward the formulation

of higher-level languages oriented toward problems in modeling human*/*mental processes.

References

1. Feigenbaum, E. A. An information processing theory of verbal learning.

The RAND Corp. Paper P-1817 (Oct. 1959).

2. Feigenbaum, E. A. The simulation of verbal learning behavior. Proc.

Western Joint Comput. Conf. 19 (1961), 121-132.

3. Feigenbaum, E. A., and Simon, H. A. Performance of a reading task by an

elementary perceiving and memorizing program. The RAND Corp. Paper

P-2358 (July 1961).

4. Feigenbaum, E. A», and Simon, 11. A. Forgetting in an association

memory. Preprints of the 16th Nat. Conf. ACM 16 (1961), 202-205.

5. Feigenbaum, B. A., and Simon, H. A. A theory of the serial position

effect. The RAND Corp. Paper P-2375 (July 1961).

6. Feigenbaum, E. A., and Simon, H. A. Generalization of an elementary

perceiving and memorizing machine. Preprints of the Second Int. Conf.

on Information Processing, Munich, 1962 (forthcoming)

7. Newell, A. f et al.. Information Processing Language V Manual. Engle-

wood Cliffs, New Jersey: Prentice-Hall, 1961.

8. Newell, A., and H. A. Simon. Computer simulation of human thinking.

Science, 1961, 134. 2011-2017, December.

5. Feigenbaum, E. A., and Simon, H. A. A theory of the serial position

effect. The HAND Corp. Paper P-2375 (July 1961).

6. Feigenbaum, E. A., and Simon, H. A. Generalization of an elementary

perceiving and memorizing machine. Preprints of the Second Int. Conf.

on Information Processing, Munich, 1962 (forthcoming).

7. Newell, A., et al., Info.rmatlon Processing; Language V Manual, Bngl*-

wood Cliffs, New Jersey: Prantice-tlall, 1961.

8. Newell, A., and H. A. Simon. Computer simulation of human thinking.

Science. 1961, 134, 2011-2017, December.