Construction of Individualized Texts for the Transmission of Knowledge Through Discourse

KNOWLEOGE ANDLANGUAGE I. Kurcz, G.W. Shugar and J .H.Danks (editors) ' ElsevierScience Publishers B.V. (North-Holland), 1986

189

CONSTRUCTION OF INDIVIDUALIZED TEXTS FOR THE TRANSMISSION OF KNOWLEDGE THROUGH DISCOURSE Jean-Francois Le Ny, Luc Carite and Sebastien Poitrenaud

A cognitive system for computer-assisted instruction, called CINACC (for Computation of Information Necessary for Acquisition or Correction of Knowled~e), is present› ed. It is designed to create in students memory a pre› determined "final state of knowledge", which is de› scribed as a set of elementary mental propositions. Knowledge is transmitted through text items which are stored in the computer’s memory and can be presented to the students on a video screen. Questions are put to the students during the study, and their responses are evaluated by the system. The outputs of this evaluation are used to determine the presentation of subsequent text items, or questions, according to predetermined rules. So during a particular session of instruction, each student is presented with his or her own individ› ualized text and set of questions, constructed by the system. Questions belong to several types: some are conceptual questions, such as, "What is an X?", in which X designates a concept. An automaton, using pro› cedures from Artificial Intelligence and special cog› nitive schemata, enables the analysis and evaluation by the system of written responses to such conceptual questions. The system in general, and the analyzer-ev~ uator in particular, help psychologists to make explic› it the links between language and declarative knowledge during acquisition of knowledge. This paper is based on more extensive

ress,

whose main ideas have been presented

Denhiere, 1982). Here we discuss

now in prog›

elsewhere

(Le Ny

&

theoretical

assumptions

The task we have undertaken is the development

of what may

underlying our research encountered.

be termed

~

some

research

and a few of the new problems

cotnitive system

of computer-assisted

The first version of this system viates the French for something

mation Necessary

for Acquisition

we have

teaching."

was named CINNA, which abbre›

like

"Computation

of Knowledge."

of New Infor›

The second

ver-

J.-F. Le Ny. L. Carite and S. Poitrenaud

190

sion is now completed;

it is named CINACC, i.e.,

of Information Necessary

edge."

for Acquisition

CINNA/CINACC was conceived

as a didactic

creating in the memory of the student some

of knowledge.

In order to achieve

endowed with the combined son’s

signed

Micromega),

specifically

resources

a specialized

for analysis

system

of

state

of a microcomputer

program, and procedures of cognition.

(Thom› de›

Students are pre›

and work in inter›

that this approach will provide new data and fresh

about acquisition

pecially

capable

predetermined

sented with written material in this context We hope

of Knowl›

this, CINNA/CINACC has been

action with the system. evidence

"Computation

or Correction

texts.

of knowledge

through discourse,

es›

SOME THEORETICAL ASSUMPTIONS The A in CINNA/CINACC refers

assimilation, for example

of knowledge

to a student’s acquisition,

about some

domain or subdomain,

a part of a chapter in meteorology,

psychology.

This knowledge

hending texts.

physics,

or ~

or

is acquired by reading and compre›

It must be brought about in such a way and to

such a standard that the student can later use it effectively

to perform various cognitive

identify concepts,

discourse.

similation"

solve

tasks:

problems,

From the perspective

analyze specific

and comprehend

of cognitive

here amounts to "deep

situations,

and produce

psychology,

memorization",

"as›

i.e., acqui›

sition of highly retrievable knowledge.

So CINNA/CINACC may be defined as a didactic

system

whose

aim is to create, in the student’s memory, some complex Jtstate of knowledge Jt regarding the domain ~. The first question, there› fore,

is how to characterize

tem considers called

or describe

Jttarget states of knowledge." ~.

the latter being

In the case

target state is defined relative to some

ing domain

such a state. The sys›

both actual and intended states,

of CINACC the

future time tf’ regard›

191

Transmission of Knowledge through Discourse

The general assumptions

edge

we use for the acquisition of knowl›

by reading a text are the following:

1. Before

a teaching session,

state of knowledge,

the student is in an initial

SKi’ regarding D. He or she may know

little, or much about

nothin~

Q.

2. As the student reads the text, he or she processes

presumably

comprehends

it, and stores

in his or her long-term memory.

many related successive

the knowledge

thus gained

As the student reads,

states of knowledge,

then,

one for each mo›

ment of time, follow

one upon another within the memory.

in empirical studies

may vary with the specific

time interval we have to take into consideration the research

or of the actual application.

3. After a session,

knowledge,

SKf,

Of course,

sessions

regarding

requirements

will presumably

be modi›

by forgetting and other phenomena.

this into consideration. concerning

Q.

Let us suppose

In this case,

that two

the student’s

initial state of knowledge

in session

between the end of session

1 and the beginning of session

uct of knowledge

2 will be the joint prod›

acquired during session

1 and of its evolution

we are reset to point 1 above. 4. For any Q, any session,

target state of knowledge.

and any student, the system

The goal of the system

the actual final state of the student’s knowledge possible

to the target state. The problem,

any teacher,

is to calculate

the best,

shortest,

as close

in particular, in psychology,

For present purposes,

and most effi›

Although

in cognitive

to a

this ques›

science,

and,

we can give a tentative answer.

a state of knowledge

as a set of psychological

as

How can a state of knowl›

(of a given domain) be characterized?

tion is still a matter of research

has a

for CINACC as for

predetermined target state.

To return to our initial question:

2; so,

is to bring

cient path from an initial state of a student’s knowledge

edge

of

Q and the session.

this state of knowledge

are held

The

in theory or

the student is in a given final state of

fied after the session, CINACC takes

it,

propositions,

will be characterized

each

containing a predi-

192

J.-F. Le Ny, L. Carite and S. Poitrenaud

cate and one or more arguments.

here to psychological knowledge

proposition

Several types

Propositions

of connectives,

as and, or, because,

Eefore,

etc.,

may also

refers

components

within the student’s mind (we prefer to say,

the student’s memory).

ments.

Psychological

entities taken as cognitive

within

be taken as argu›

logical

or semantic,

such

are used to relate these

positions.

Thus the set of propositions

chological

propositions

of

has a structure and

pro›

might alternatively be presented as a graph. This use of psy› of text, especially

is fairly common

of stories

in cognitive

(for example.

Denhisre,

analysis 1982;

& Le Ny. 1979; van Dijk & Kintsch. 1983; Kintsch & van

Denhisre

Dijk, 1978; Le Ny, 1979).

with texts that convey important differences

CINACC deals

a didactic

in the same general way

content,

although there are

as regards the content of the concepts

involved. We shall return later to this question of concepts. Below is a sample

mentary meteorology, 1.

HEAT

(cx,fJ)

3.

SEND

(ex,B.

2.

BECAUSE

where

0: =

set of propositions

comprising

((1.),

in the domain of ele›

fairly simple

(3.))

sunbeams)

the sun, B = the earth

The set might correspond to texts such as:

earth because sends

concepts.

sunbeams

it sends

sunbeams

"The

to the earth,"

to the earth and, therefore.

sun heats the

or "The

sun

it heats the earth,"

or "The heating of the earth (by the sun) is due to the fact that the sun sends

sunbeams

Standard logicians,

chologists,

postulate

to the earth."

and, following

the existence

their example,

of a constituent

many psy› of dis›

course.

the proposition, which has the same predicative form or

cording

to this assumption,

structure as that just used

with the syntactic

in the discussion

sentences

and semantic rules

bring about adequate processing

knowledge

in the students’

In this view, a sentence

produced

of knowledge.

in accordance

Ac›

of language are able to

and, thereafter, adequate

minds. ~

fied on two different grounds.

is something

that can be identi›

First, on physical

grounds

(or

Transmission of Knowledge through Discourse

193

on grounds that can be analyzed as such), ~ is a certain bundle of acoustic or visual stimuli or cues. Second, on a functional level, the communicative role played by a sentence consists, under specific linguistic and pragmatic conditions, in creating some psychological proposition in the working memory of a per› son, and later on in his or her long-term memory. Theoretically, t.nI s comes down to assuming that at least some of the knowledge stored in the mind is present in a form isomorphic to, or at least compatible with, discourse. This seems to be close to Vygotsky’s (1962) view. A similar point of view has been presented, though in a rather different theoretical con› text, by J. Fodor (1975), who called such a form "the language of thought." This does not come down to saying that all knowl› edge necessarily takes on such form: perceptual, imaginal, and procedural knowledge may also be considered to exist in a simi› lar or a different form. As a matter of fact, the notions con› nected with the expressions propositional and imaginal are in no way mutually exclusive (Denis, 1979; Denis & Le Ny, 1984; Le Ny, 1979). By definition, CINACC handles only those types of knowledge that can be created or modified by discourse, or more precisely, by reading. Let us summarize how reading is assumed to operate on two different states of knowledge. We shall call one of these the current state of knowledge (about D) for a given student at a given time. We shall call the other the next target state of knowledge, to be reached by this student at some near future time. Observe that it is in the teacher’s mind that this target exists as a cognitive content of his or her intentional task of teaching. For instance, at some time, a particulax student does not yet know that a fraction of the energy emitted by the sun as sunbeams is absorbed by the earth’s atmosphere, that a sec› ond fraction is reflected by the earth’s surface, and that a third fraction is absorbed, and is stored, by the earth. A tea› cher’s next target may be to bring about a particular state of knowledge in which the new propositions corresponding to this

J.-F. Le Ny, L. Carite and S. Poitrenaud

194

knowledge

are contained in the student’s memory.

of CINACC is that such a target may be included

as a subtarget of some

specific

program.

Ihemilln tasks of CINACC consist

rent state of knowledge sessing

the difference

The principle

into the system

in evaluating a student’s

concerning

some

cur›

item of knowledge,

as›

between the current state and the next

target state, and in light of this difference,

next item of information to be presented

deciding

on the

to the student, so as

to allow him or her to attain the next target state. These

may be summarized briefly possible

steps:

1) student h does 2) but student

3) therefore,

and simply as involving the following

not know that £i’

h should know that £i’

let us present ~ with an item of text tt

where the item of text tt of an item of knowledge,

These

tasks are performed

get states.

All these

targets

structures

text and so progressively

edge

by a final state

i, to be an expression

is assumed

i £i’

for successive

ward achieving the final goal: their cognitive

tasks

current and next tar›

(or subtargets)

by processing

successive

items of

to the final tar›

get state determined by the teacher.

states of knowledge

to›

replacing the initial state of knowl›

as similar as possible

As pointed out before,

are directed

to have the students transform

the way in which the intermediate

are taken into account

depends

on the choice

of time interval or unit and on the size of the information

bundles adopted.

In the first version,

the bundle that CINNA

usually dealt with was the short paragraph, but CINACC can as

well deal with complete or concepts.

As the system

or elementary

provides

sentences,

computer-composed

word meanings,

texts on which stu›

dents work individually, its main advantage is to individualize the choice

and order of the sentences

or paragraphs that con›

stitute a text so that each particular student can be presented

with his or her own particular text or sequence accordance with predetermined cognitive rules.

of texts,

in

Transmission of Knowledge through Discourse

195

STRUCTURE AND OPERATION OF THE SYSTEM We shall now briefly describe how the system is constructed and how it works. For convenience we present this description so as to correspond with the preceding description of the sys› tem’s three main tasks. These tasks may be analyzed into three components: 1) does student g know that Ei? -- the two alternative re›

sponses being y or n (for "yes" and "no"); 2) given two alternative items of text, tt 1 and tt 2, decide: if 1) = n, then tt otherwise tt2; 1, 3) present g with the chosen item of text. Thus, the three components are: (1) questions (about states of knowledge), (2) decisions (about presentations), (3) presentations (of text items). Accordingly, the system works from three main sets of data, which have been set up in advance in three different files in the computer’s memory. Let us begin with the file corresponding to step (3). This file contains a set of text items. In the first applications, these are, as has been said, paragraphs, sentences, and parts or skeletons of sentences concerning the domain; these text items, or texts, convey all the information needed to instruct any student -- from a predetermined population -- in the domain in question. In other words, they convey all the information that the students need to process as their previous knowledge is changed in direction of the target state of knowledge. Of course, the content of this file is determined by an expert teacher of the particular subject matter of the domain. The file corresponding to step ~) contains a set of questions the students are asked at predetermined times, in order to evaluate their successive states of knowledge. As shown in the general "question" schema outlined above as task 1, possible responses have to be explicitly stored in the file in addition to the questions, since evaluation of the actual responses is a necessary part of the task of questioning in the system. In

J.-F. t» Ny, L. Carite and S. Poitrenaud

196

general,

a student’s actual response

it with one of the predicted complex

process:

a very simple

controlling

and we shall introduce

further below.

The second

questions,

Such matching can be a

the alternative we presented

case,

possibilities

is evaluated by matching

responses.

file

in the system

contains the decision

the presentation of text items,

in accordance rules.

(1) If subject

£

rules

or of subsequent

with the evaluations obtained as the

output from the questioning process.

as production

(y or n) is only

more sophisticated

These rules are organized

The simplest schema

E~

has given response

for them is:

~i,

to question

present him with text tt and afterwards with question w Of course,

more

schemata

~omplex

can be used,

then

~k

such as,

(2) If subject h has given response r i or response r i to ques› . - . -a. -c. and . tion ~l, and response ~ or response £~ to question ~J,

etc.,

the present him or her with text tt followed by text v’ I by text tt and afterwards with question ~ , etc. z’

ttw’ followed So,

in this respect,

based

system

designed

the architecture

The contenre of the text, question,

have to be conceived

didactic

texts,

practice.

or as a field for cognitive

and decision

ing a large set of psychological processing,

rules are considered hypotheses

as involv›

concerning

question answering, structure of concepts,

One kind of current research

re›

point of view,

vance of rules assigning texts or further questions ses.

all

itself may be viewed as a matrer

From the present experimental cognitive

questions,

rule files

and general didactic

expertise

of pure empirical experience search.

and decision

and organized by an expert with regard to

both the domain of knowledge Actually,

of CINACC is a knowledge›

for the solution of teaching problems.

text

and rele›

to respon›

based on this system

consists

in studying the various routes that various students follow

through the network of knowledge

nothing more about such research

enough data to reach conclusions. on the particular types

so provided.

here,

We shall say

as we have not collected

We shall, however,

of questions

elaborate

and their evaluation.

Transmission of Knowledge through Discourse

197

TYPES OF QUESTIONS All in all, we use three categories of questions, with three corresponding degrees of complexity involved in their evalua› tion. One category contains conventional multiple-choice gues› tions. The students respond to these by pressing on the key› board, in accordance with previous instructions, the key they judge appropriate for their response. The system’s evaluation of these responses and the decision on the next presentation are then direct. Examples of such questions are presumably not needed. This type of question, with the possible responses and the corresponding decision rules, is not necessarily trivial. In addition, such questions are often used as the final step after a series of more complex questions. A second category consists of open guestions with a limited range of possible responses. Only the teacher or experimenter knows that this range is limited, so that they appear to the students to be true open questions. Responses are evaluated by the identification of key words. Thus, in the program, there is a fourth file which contains labeled classes of words. Let us illustrate their role by an example taken from classroom teach› ing of psychology. After students have read a chapter of text taken from an introductory handbook in the psychology of memory. they can be asked: What are the successive phases that psycholo› gists have, as a rule, distinguished in the study of memory? The correct reponse is of course some combination of words including at least three words such as fixation, storage, and retrieval. But many other words may be considered acceptable as they pertain to the same classes as the words just mentioned. So we can state that a correct response includes at least one word of the class "fixation", plus one of the class "storage", plus one of the class "retrieval". In the third class, for in› stance, we can decide to accept, in addition to retrieval, such words as recall, recollection, reactivation, access, recogni› tion, etc., as well as the corresponding verbs. The file will contain only word skeletons, such as "reactiv-", so as to per› mit matching with "reactivates", "reactivated", etc., as well

198

I.-F. Le Ny, L. Carite and S. Poitrenaud

as with "reactivation".

Everything in the file

rclevant decision

Such evaluation by key words may be ap›

pert in the subject

matter, too,

rules.

plied to a large range of open questions,

kinds of wh- questions:

which,

including various

when. where, etc.

But let us now examine our third category

shall call them conceptual "What is an X?",

concept

guestions.

in the domain under study.

are not intended to elicit

they are not intended to elicit a response conditions

ther a text expressing

mind which are related to the concept not consider A special

the elicited

(Woods,

1975) which produces

sponses

consists

interpretation and evalua› This subprogram

Transition Network type

is a

a definite abstract representation

given by the student. Evaluation of such re›

in trying to match this abstract representation

of the current response

previously

The teacher mayor may

to do this job.

semantic analyzer of the Augmented

of the response

being an X, but ra›

units in the subject’s

text appropriate.

subprogram of discoure

tion is being implemented

X.

true definitions

In other words,

stating the necessa›

for something

a set of semantic

We

usually an important

from a student but rather characterizations. ry and sufficient

of questions.

They are of the type:

with X being a concept,

These questions

is up to the ex›

and so is the statement of the

introduced

the expert teacher.

ral process.

with an abstract target representation

into the machine under instructions

Figure 1 presents

of

an outline of this gene›

The machine program of analysis and interpretation extracts

the relevant information from the subject’s

vides the system

of this response.

archized couples,

response

with an intermediate semantic

and pro›

representation

This representation is in the form of hier›

each of which consists

of one attribute and

one value of this attribute. This state is intended to mimic

human comprehension.

The evaluation program compares

this intermediate representa›

tion with a target representation of the concept

under consider-

199

Transmission of Knowledge through Discourse

ation. (Such type representations

are exemplified

in Tables 2

and 3.) This stage is intended to mimic evaluation by a human judge.

The evaluated representation of the response.

i.e., the

output of the program’s evaluation, is in a form usable

left part of the decision

ditional questions)

c rules.

follows

Presentation of texts

from their application.

SUbject’s response

~ncerning

as the

(or ad›

X

I I I I I

AUTOMATON I

[ -

. ----Intermediate semantic ,t; representation of the response

~

Evaluation program Target type representation

_ _CJ.f

~

_

Evaluated representation of the response

I

) IText presentRtion

Figure 1. General procedure

for response

evaluation.

I

200

J.-F. Le Ny. L. Carite and S. Poitrenaud

EVALUATION OF RESPONSES In this paper we shall not describe the subprogram used as a semantic analyzer and interpreter of texts. Instead, we shall sketch the information structure used to evaluate students’ re› sponses to conceptual questions. We shall exemplify this sketch with two psychological concepts, "f’or-ge t t i.ng" and "interference". We assume that the concept "forgetting!! is present, with an appropriate basic content, in the initial knowledge of any stu› dent belonging to a normal population. In contrast, we assume that initially the uninstructed subjects have no concept of "interference I! with a meaning relating to scientific psychology. But this concept may be considered an important item of knowl› edge to be included in a target state of knowledge for a teach› ing session devoted to the subdomain of !!forgetting". The two concepts should be present in a student’s final state in a way that can be expressed as FACTOR OF (interference, forgetting). "Interference I! (and I!forgettingl!) can be used here in either a causative or a merely descriptive sense, depending on the gen› ~ru epistemological view of the user. Our illustrative use of these concepts here does not commit us to either view. The teacher must specify in the outline of the target state of knowledge which items of meaning he or she considers to be essential to characterize any new concept introduced (in this case, I!interference"). Items of meaning here refers to items of knowledge that are assumed to be basic to the target concepts, and to the interrelationships of these items. They are consid› ered basic here in that they would already be known by the stu› dents and are so unambiguous that there is no need to verify their meaning for any student. In other cases, they may be iwms of meaning that have been already verified during this or some previous session with a given student. Let us illustrate this with the concept I!interference!! by stating what the target re› presentation of this concept should contain. First, it should refer in this context to I!learning!!. In the same way as forl!forgettingl!, we have good reason to believe that

201

Transmission of Knowledge through Discourse

an average student knows what learning is, at least well enough for our purpose. So "learning" will be considered a basic item of knowledge in our program , and will not have to be verified. In addition, the target representation should state that "inter› ference" involves (at least) two situations and processes of learning, and that the two processes interact so that perform› ance is worse for one of them if the other has taken place than if it has not. But we must describe this interaction in a pre› cise way in the target representation, in particular as con› cerns time relationships between learning situations and proc› esses. Either the interfering situation occurs before the other, in which case proactive interference is produced, or else it occurs after, in which case retroactive interferenoe is produred. Furthermore, we must take into account the possibility of improvement in performance (i.e., of transfer) rather than im› pairment (i.e., interference) after the two processes have in› teracted. Accordingly, we may state the target representation of the two interrelated concepts of "interference" and "transfer" as an equivalence formula (in quasi-natural language, as proposed by the authors; various wordings may express it in the teach› er’s or student’s language): For any couple, ~, ~, of learning situations in a subject (given an appropriate description of "learning situation" and "performance due to the previous learning situation"): 1- IFF performance on :2 WHEN 1l, PRECEDES £ IS INFERIOR TO performance on £ WHEN 1l, DOES NOT PRECEDE £ THEN this ifj proactive interference (of ~ with ~) 2. IFF

[replacing with and with in rule 1]

performance performance PRECEDES FOLLOWS

.

on £ on g (at an appropriate time)

202

J.-F. Le Nv. L. Carite and S. Poitrenaud

performance on a (subsequent to 2) WHEN ~ FOLLOWS !2: IS INFERIOR TO performance on a (at a corresponding time) WHEN E DOES NOT FOLLOW ~ THEN interference (of b with !!) is retroactive this 3. and 4. IFF [substitute IS SUPERIOR TO for IS INFERIOR TO in rules 1 and 2J THEN this is proactive transfer or retroactive transfer, respectively. Thus we have systematically characterized four interrelated concept~ among which "retroactive transfer" is a possibility, though barely mentioned in published reports. This type of char› acterization is used in GINACC in three ways: as part of the target state of knowledge, as a description of the basic seman› tic information the students are presented with during the ses› sion (about "interference"), and as a machine representation to be matched by the student’s responses to open questions of the type, "What is I?". In this case the question would be, "What is interference?". Since this triple use of the same representation might be confusing when we describe how responses to open questions are evaluated, we shall now use the second example, namely "forget› ting". As we have said, at least the crude concept "forgetting" is assumed to be present in the initial state of knowledge of an average student. Of course, it will also be present, but en› riched -- i.e., be broader and more precise -- in the final state of knowledge. But let us for the moment consider just the initial state of knowledge. The concept "forgetting" can be characterized in exactly same general way as "interference" was.

the

The assumption that the student is familiar with "forgetting~ no matter how the concept may have been acquired, leads to the following consequence: for our characterization to be correct,

Transmission of Knowledge through Discourse

203

it must be able to match a set of students’ actual responses (made before any lecture or learning session) to the question. "What is forgetting?". So we first set up a formula characterizing "forgetting". Then we asked twenty subjects to give a short descriptive re› sponse to the question. "What is forgetting?", and we analyzed their response texts with respect to our characterization. Be› low is our initial formula characterizing "forgetting" as unde~ stood by the average student at the outset. Observe that "for› getting" refers to a state ("to have forgotten") rather than a process ("to forget"); only focal items of knowledge are repre› sented (cf. Figure 2). For any individual x and for any content y. IFF at time t5, x NO LONGER KNOWS Y or x CAN NO LONGER REACTIVATE Y WHEREAS at some previous time t3. x KNEW y or x COULD REACTIVATE Y THENt h i s is forgetting In this context "forgetting" involves two main contrasted items of knowledge. or components of meaning, which are them› selves composed of several more basic components. The focal item of knowledge is that some individual. x. no longer knows or can no longer reactivate (recall. remember. etc~ some content, y. at some time. called t5. A second item of

knowledge may be said to be "presupposed" by the words "no long› er (knows)". used above. But we think it is more correct to say that the second item of knowledge is also a part of the con› cept "forgetting". or of the meaning of the word forgetting: that x knew y. or could remember y. at some time, t3. prior to the focal time. t5. A third item of knowledge

is implicit in this characteriza›

tion: that the state at t3 ("x knew y") had been acquired. i.e., had been achieved through some learning or memorization that

Figure 2.

Analysis

~

I

y

x knows y

~

t5

t4

to successive

Contrast

Y’

J

of time.

I

Focal period

periods

,

x no longer knows y (x has forgotten

Forgetting (state of)

Forgetting (process of)

x comes not to know y (x forgets y)

of forgetting with reference

x comes to know y

t3

t2

t1

x does not know y

IVJemory

IVJemorization (learning)

Ignorance

y)

~

is

~.

cl’

~

’l:l."

’";::

~.

D

t:-"

’" ~

t-o

~

~

~

N

Transmission of Knowledge through Discourse

205

had taken place at a still earlier time, t2. Before t2, there was an initial state of ignorance, at t1. For the sake of com› pleteness, one more time should be considered, t4, at which a process formally symmetrical to learning takes place: forget› ting. During this process, x partially knows y, or sometimes can reactivate y and sometimes cannot. So "forgetting" is char› acterized in our formula as complete forgetting; i.e., as the end product of the process of forgetting. Our assumption is that this is the dominant (prototypical) sense of "forgetting" in the average student’s mind. Figure 2 presents this analysis diagrammatically. All times mentioned ~ this characterization are periods. Ho~ ever, it would be feasible to consider any instant of time ti, such as ti5, as being an instant of time in the period t5, etc. We said that the focal knowledge in our formula is "x no longer knows y", £E. "x can no longer reactivate y". We could add "reactivate y either in an external (behavioral) or in an internal (mental) way". So such a characterization may contain disjunctions. It must be emphasized that our forula is assumed to charac› terize an initial concept for uninstructed students. We assume that for such students the following relationships hold -- at least as a correct first approximation: if x knows y, then x is able to reactivate y; if y is able to reactivate y, then x knows y. A sentence like the second one is used by cognitive psychologists too, as a tool for inference. But the first sen› tence needs to be elaborated further. One goal of the instruc› tion may be to convey information about notions such as "acces› sibility" in memory. In that case, the characterization of the final target concept of forgetting should contain some kind of distinction between "x no longer knows y" and "x can no longer reactivate y". We do not address this distinction in this paper. In order to validate the formula of "forgetting" we have to look at every written reponse to the question, "What is forget› ting?" for words or phrases that can be confidently taken to ex› press linguistically the existence in the student’s mind of the

J.-F. Le Ny, L. Cariteand S. Poitrenaud

206

following

items of knowledge:

1. an individual, X;

2. a mnesic content, y; (both X and y must appear in an undetermined form, some

universal quantifier);

or with

3, a relation R between x and y, which may be either 3.1. x knows y or

3.2. x can reactivate y

4.

as discussed

above;

a negation;

5, a time contrast associated

with the negation, such as:

t5), the relation R has a

5.1. at a later time (called negative value,

5.2. whereas

5.3. previously either

the relation had a positive

value, i.e.,

5.3.1. x knew y (at t3)

or

5.3.2. x could

reactivate y (at t3)

or

5.3.3. x acquired y (at t2)

(which entails 5.3.1. or 5.3.2).

These

items of the characterization are then used as the ele›

menw of a conceptual or phrases example,

schema.

For each element,

can be listed a priori as possible

students may express

or gQ more.

R may be expressed

as various forms

to recall,

x can be expressed

££ --

to recollect,

the lists are different in French. For example, as

sometimes

~

appear as some

student, etc.

of the verbs

etc.

Of course,

the undetermined

more frequent in French than one in

(someone,

somebody).

Moreover,

x may

determined name or noun, such as John,

It may not be expressed

is infinitive. If some

For

the negation as not, no longer,

to know, to remember,

English -- or as guelgu’un

a set of words

instances.

word is used,

at all if the verb form

it must alwBys refer to

the same individual who does not know at t5 but who did know at 0 .

207

Transmission of Knowledge through Discourse

The time contrast is normally expressed

time difference

ample,

pressed

ly.

"x does

not know y, x new y".

But some

In French this is best ex›

(passe

compose

the aspectual

The preceding

example

at t2 can be expressed

information conveyed the previous

with it.

also

shows

indirectly.

to lead by inference

particular statements

of the conceptual

every subject

or an event (learn›

how an event taking place

to "to

and inferences

schema

is presumably

have put in one’s

memory".

are not included

to represent

can later be extended

by ob›

of fresh data. In the present case,

may be assumed

produced

by subjects

be interpreted as due to awkwardness in expression This will not be so for more complex

The texts of 20 responses

presented

above.

undergraduate students who had received

about memory,

"forgetting"

The subjects

and in particular about forgetting. framework.

with in

were 20

no direct instruction

es were acquainted with the notion of matching,

an Artificial Intelligence

can

rather

concepts.

were analyzed by two judges

regard to the characterization of the concept the form of the schema

since

to know the crude meaning of for›

getting, any bizarre words or phrases than to ignorance.

in

Naturally, any cur›

wordings used in discourse

servation and analysis

safely

bv the

time may be either

"To have seen"

and will be treated separately.

rent set of possible elements

for instance

or plus gue parfait), as

t3 or t2, and so either a state (knowledge)

ing) is accordingly’associated

the schema

respective›

is different in French from that in English. As is

mentioned in 5.3 of the schema,

supposed

tenses,

is no longer able to remember what he had once

Of course,

past tenses

of R: for ex›

other past tense may be used as well,

or pluperfect

in, "Somebody

These

by a grammatical

instances

by use of the present and imperfect

perfect seen."

between two successive

In a sense,

The two judg›

considered

what they

in

tried to do was to simulate in their own minds what a machine

program would do when matching an input text to a predeter›

mined schema.

People

mimicking machines

best thing in the psychological Matching was directly

world!

successful

may be the worst or the

for 17 of the 20 response

208

J.-F. Le

texts: cue

in everyone

there was a word, phrase,

-- for example,

a predetermined ed above.

Some

formation;

»s. L. Cariteand S. Poitrenaud

instance

be matched to

of each item of the schema

responses

as present›

contained redundant or irrelevant in›

the rule for this aruDysis had been stated so that

any extra information was diregarded. information was therefore

problem

or morphological

a sign of tense -- that could

discarded,

Redundant or irrelevant

as there was no important

in applying this rule to these

For twc other response

most parts of the schema,

texts,

matching was succecsful

but some

problems

to the kind of problem exemplified text could

be considered

saw, heard, and experienced" committed

hear, to experience of saying,

"to

some

for

They belonged

words in the

of an element

of the sche›

"what someone

be interpreted as implying

to memory".

in the case

arose.

-- for instance,

could

deal with each particular case of the lexicon:

above:

as instances

ma only via a one-step inference "what someone

texts.

It would be possible

to

of this kind by an accommodation

mentioned,

we could

put to see,

into the list of words considered

learn at t2."

But this is a rather ad hoc

tion. A better one, allowing interpretation by inference,

be constructed

in the future;

be knowledge-based cific

information that could

no longer remembering

hardly be matched

has to

that it was necessary

This example

to aJ.low a lexical

solution:

For such

such a large lexicon

to the predeter›

Here is ilia rosponse:

bread for lunch."

overspecification.

solu›

shoul~

text contained a large amount of very spe›

mined wordings of the schema.

=

such a solution obviously

and not purely logical.

One last reponse

to

as ways

clearly

cases,

too,

we could

"Forgetting

to buy a loaf of

provides an example

of

it would be conceivable

provide the system

that the words in it could

with

be matched by

very many token words in the texts,

if not by all. But this

What CINACC would do

would be to apply a simple

woule be uneconomical special

rule:

(according

response

reSDonse

and clearly

could

in such a case

If the program fails

not be exhaustive.

to construct

a satisfactory

to determined criteria) representation of a subject’s

text, ask the sUbject: to this question?".

"Would

you please

rephrase your

209

Transmission of Knowledge through Discourse

In accordance

interpreter, some

with the present limitations of the system’s constraints have to be imposed

texts it can take as input. These (1) Reponse

length:

(2) Response

type:

concern

for the time being,

cept responses

longer than 4 lines

with questions

of the type,

deal with incorrect

or complex

of analysis

could

of the response

possibly

not ac› only

text: More

be set up in order to

response

texts.

But it is not

our main goal at present to interpret every single since

does

4 x 80 characters).

(i.e.,

"What is an I?".

and simplicity

forms

the system

as has been said, the interpreter deals

(3) The correctness

complex

on the response

the following:

response,

the restatement rule mentioned earlier can always be used.

Moreover,

the requirement made by this rule may be considered

appropriate in an instructional session. The same kind of analysis

as for "forgetting"

either to an initial, pre-session

tained during a session, similar to those

reponse,

or to a response

presented

in our two formulas

with the text presented

has been set up.

questions

schemata.

component

fore,

Some

makes

concepts

hypothetical

false

the program could

some

response

from cognitive

schema

schema

some

There›

a corresponding

from mismatches,

with. From such

diagnosis

because

to be used as a means of teaching:

identify which incorrect

matches

conceptual

conceptual

is added.

not only distinguish matches

students have acquired

rules

or a component

to enter into the system

to the correct

the latter case,

to open,

to set up false

are often misunderstood

in them is missing,

it is possible

responses

it possible

has to be made

during the session.

In addition, the evaluation of responses

"wh-"

ob›

provided an appropriate representation

Naturally, evaluation of non-initial responses in accordance

can be applied

about concept

but also,

conceptual

schema

identifications,

of what is incorrect

of presentation in the system,

of students’

in

i.e.,

in the knowledge

I, we can, by appropriate

decide

which items of in›

formation have to be transmitted to each particular student in order to improve

In this section,

his or her knowledge we described

of I.

in some

detail the third cate-

210

J.-F. Le Ny. L. Carite and S' Poitrenaud

gory of evaluation in CINACC. All three categories of evaluation involve, as is now clear from tbese descriptions, inferences by the system -- based on rules given by the conceiver -- that lead to a representation of what the student’s current state of knowledge is. In all these evaluations, two more main psycho› gical concepts are used in connection with student knowledge: first, the accessibility to tr.e student of his or her own knowledge, and second, the degree of confidence the student bas in tbis knowledge. These concepts, which are widely used in psychology, will not ce elaborated on in this paper. CONCLUSION We may now summarize how the whole system works, and what is postulated in it from a cognitive point of view. CINNA/CINACC has been devised as a tool that closely language and knowledge.

links

First, it uses language in order to crea~ knowledge. So, this knowledge bears no direct relationship to the world in the course of its acquisition. In this respect, it may be said that such knowledge, once acquired, is different from "natural" knowledge, which is directly extracted from or related to the perceptible world. Recent psychological studies on semantic memory (e.g., Anderson, 1976; Collins & Quillian, 1969; Dubois, 1982; Johnson-Laird, 1983; Klix, Hoffmann, & van der Meer. 1982; Le Ny, 1979, 1982; Norman & Bobrow, 1979; Rips. Shoben, & Smith, 1973; Rosch, 1978; Rumelhart & Ortony, 1977; Smith & Medin, 1981; Tversky, 1977) have been primarily concerned with natural terms, or related ones, i.e., with concepts or word meanings such as "dog", "table", "under", "to move", which are presumably both acquired and maintained by frequent interactions between discourse and perception of the world. It might be argued that the word-meaning II forgetting" belongs to this same category of knowledge in that it is rooted in every subject’s experience, even though not in perception proper. By contrast. a concept such as "interference" can be created only by the use of lan› guage.

211

Transmission of Knowledge through Discourse

However, in instructional discourse,

in general are always assumed

to refer to some of reference

concepts

to be about the real world, and

entity or relation in it. So whatever theory

is adopted,

be related to some

the knowledge

parts or aspects

imparted

takes into consideration

data.

or on words,

consider

cally

special

methodology,

phrases,

therefore,

which

acquired

students rely

and sentence

in or related to perception.

knowledge

to

both observational and inferential

When reading instructional texts,

are rooted

is assumed

of the world via percep›

tion. This relation is granted by scientific

on concepts

and knowledge

meanings that

This is why we cannot

by language processing

kind of knowledge.

as a radi›

However. the conditions

of its

acquisition -- reading a text -- certainly raise psychological

problems

that are somewhat different from those

recent years crete

in cognitive

knowledge. system

A second

and language are linked in a computer›

aspect

of the relationship between language and

in CINACC is worth emphasizing.

assessing

their knowledge.

ments made by the students in repsonse theoretical

The system

to questions

evaluation refers In summary.

views about the

CINACC is clearly (Newell,

both on knowledge

a knowledge-based

in

use the

1982). This means that it has to rely

and on knowledge

Firstly, it requires

between two such experts.

Secondly.

managed by an expert

interactive communication it provides

data that allow interactive communication system)

system

specialists

provided by an expert in the domain or subdo›

main under consideration

in cognition.

in which

to "gaining external knowledge

in which Artificial Intelligence

word knowledge

state›

In the latter part of this paper we

and semi-technical

specifically

of internal knowledge".

uses

as a way of

interpretation and evaluation programs of the system,

the sense

is one

such as CINACC.

knowledge

have presented

in

with regard to more con›

This method of acquisition of knowledge

way in which knowledge assisted

psychology

discussed

procedures

between itself

and

(the

and a student, that is, an indirect interactive commu-

212

I.-F Le Ny, L. Came and S. Poitrenaud

nication between the expert in the domain, the expert in cogni› tion and the student. To make this possible, the separate ap› proaches of Cognitive Psychology and Artificial Intelligence are conjoined from a point of view that we believe may illus› trate a more comprehensive approach to Cognitive Science than is permitted by either discipline on its own. In doing so we try to make the system CINACC both a practical tool for compu› ter-assisted instruction and a research tool for the investiga› tion of the interrelations between knowledge and language. Acknowledgements The first part of the entire research project was supported by a grant from the Agence De l’Informatique (France). Valuable help was provided by the Service d’Etudes pour Ie Developpement et l’Animation (Paris). REFERENCES Anderson, J. R. (1976). Language, memory and thought. Hillsdale, NJ: Erlbaum. Collins, A. M., & Quillian, M. R. (1969). Retrieval time from semantic memory. Journal of Verbal Learning and Verbal Beha› vior, ~, 240-247. Denhiere, G. (1982). Do we really mean schemata? In J. F. Le Ny & W. Kintsch (Eds.), Language and comprehension (pp. 219› 238). Amsterdam: North-Holland. Denhiere, G., & Le Ny, J. F. (1980). Relative importance of meaningful units in comprehension and recall of narratives by children and adults. Poetics, ~, 147-161. Denis, M. Les images mentales (1979). Paris: Presses Universi› taires de France. Denis, M., & Le Ny, J. F. (1984). Centering on figurative fea› tures during the comprehension of sentences describing scenes. Paris: ERA 235. Mimeo No. 220. Dijk, T. van, & Kintsch, W. (1983). Strategies of discourse comprehension. New York: Academic Press. Dubois, D. (1982). The nature of mental representation and sen› tence comprehension. In F. Klix, J. Hoffmann, & E. van der Meer (Eds.), Cognitive research in psychology. Berlin: Verlag der Wissenschaften. -Fodor, J. A. (1975). The language of thought. Hassocks, Sussex: Harvester Press. Johnson-Laird, P. N. (1983). Mental models. Cambridge, England: Cambridge University Press.

Transmission of Knowledge through Discourse

213

Kintsch, W., & Dijk, T.A. van (1978). Toward a model of text comprehension and production. Psychological Review, ~, 363› 394. Klix, F., Hoffmann, J., & Meer, E. van der (1982). The storage of concepts and their cognitive application. In J. F. Le Ny & W. Kintsch (Eds.), Language and comprehension. Amsterdam: North-Holland. Le Ny, J. F. (1979). La semantique psychologiguo. Paris: Presses Universitaires de France. Le Ny, J. F. (1982). Knowledge, meaning, and representation: Some current problems. In F. Klix, J. Hoffmann, & E. van der Meer (Eds.), Cognitive research in psychology. Berlin: Verlag der Wissenschaften. Le Ny, J. F., & Denhiere, C. (1982). Profile of CINNA: Con› struction of individualized texts. Text, ~, 193-210. Newell, A. (1982) The knowledge level. Artificial Intelligence, l.§., 87-127. Norman, D. A., & Bobrow, D. G. (1979). Descriptions: An inter› mediate stage in memory retrieval. Cognitive Psychology, 11, 107-123. Rips, L. J., Shoben, E. J., & Smith, E. E. (1973). Semantic dis› tance and the verification of semantic relations. Journal of Verbal Learning and Verbal Behavior, ~, 1-20. -Rosch, E. (1978). Principles of categorization. In E. Rosch & B. B. Lloyd (Eds.), Cognition and categorization. Hillsdale, NJ: Erlbaum. Rumelhart, D. E., & Ortony, A. (1977). The representation of knowledge in memory. In R. C. Anderson, R. J. Spiro, & W. E. Montague (Eds.), Schooling and the acquisition of knowledge. Hillsdale, NJ: Erlbaum. Smith, E. E., & Medin, D. L. (1981). Categories and concepts. Cambridge, MA: HRrvard University Press. Tversky, A. (1977). Features of similarity. Psychological Review, g, 327-352. -Vygotsky, L. S. (1982). Thought and language. Cambridge, MA: M.I.T. Press. Woods, W. A. (1975). Syntax, semantics and speech. In D. R. Reddy (Ed.), Natural language processing (pp. 345-400). Englewood Cliffs, NJ: Prentice-Hall.