Johnson’s first articulation of his theory about how the level of abstraction of our communication — and the interfaces that underpin it — depends on what is being communicated and by whom. A more popular account is provided in the 1977 piece (also available here) called “Come Closer and We Won’t Even Have to Talk.”

ABSTRACT

Dialogue is a form of communication between respon­dents which has yet to be described or modelled adequately. A scale is proposed whose parameter is the “distance” of the referent in time and/or space from the moment and place of the dialogue itself. Its extremes are* at one end the immediacy of inti­mate contact, and at the other symbolic language where involvement with the referent is abstract, A number of observable changes correlated with move­ment along the scale are considered, and design criteria are proposed whereby the required complex­ity of an adequate interface may be predicted once its position on the scale has been recognized.

INTRODUCTION

It is the author’s intention that this paper be a contribution toward the more adequate description of com­plex system interactions. The approach is neither rigor­ous nor analytical but rather seeks to predicate a quali­tative scalar function which has been useful to him in conceptualizing levels of dialogue at a system interface. Its usefulness has been greatest for the consideration of man-machine or man-man pairings and it is presented in these contexts. It must therefore be made clear at the outset that no claim is made for the application of these notions to deductive processes: computers programmed in ad­vance to perform ritual acts. The applications that are intended are those in which an ongoing exploration of one system by another is entailed and where no final result nor homeostatic state is anticipated.

Dialogue[2],[6],[9],[10] is a communicative behavior which we have as yet been unable to describe sufficiently well to apply measure to it. The root of our problem as observers is that if we attempt to identify or separate inputs and outputs to or from the participants, we effect­ively obliterate the message and render the meaningful ex­change empty. We cannot observe the messages because the medium for each participant includes the responsiveness of the other in an infinite recursion. The isolation and identification of transitory segments of a dialogue is possible, but their meanings when embedded in the broader contexts of the dialogue itself can never fully be known unless one is himself a participant -— whereupon the meanings necessarily take on a self-referent quality know­able only to that knower. The meaning of an object or event to an organism is embodied in his consequent response (real or latent) to it; such is his way of exploring the context of its occurrence. We cannot wholly share that exploration with him. We can, however, describe a dialogue in a qualitative way and can acquire from that description a notion of the complexity of the systems involved and of the Interface required to sustain it.

THE REFERENT AND ITS DISTANCE

Any communication is about something – let us call it the “referent” –  even if that something is only the message itself. In general we may say that the referent exists within the information space that may be explored by the participants in the dialogue. Consider the idea that there may be a measure of “distance” in time and/or space between the referent and the moment and place .of the dia­logue in process and let us examine the consequences of moving along a scale of this “distance” from zero outward. Fig, 1 provides a graphical and verbal representation of five positions distributed along the scale. The illustra­tions are more or less familiar instances of man-man or man-machine interfacing situations. The positions are numbered 1 through 5 for convenience of discussion, but no implication is intended either that the possible extremes are depicted nor that equal spacings of “distance” have been achieved.

POSITION 1: The referent is the participants them­selves and their relation to each other. The communica­tion may be characterized as IMMEDIATE because in fact no media are employed apart from the responsive environment that each of the participants is for the other.

POSITION 2: We move out to where the referent is external to either participant but where their interactions with it and with each other are indistinguishable. The communication is COMMUNAL and its medium is the referent itself. Examples within the realm of man-man communica­tion are common but generally pass unrecognized as dialogue. Blind children will not learn to run or jump until they have shared the experience In direct physical contact with another person. Learning to manipulate the substances, common shapes, and culturally-established relationships of whole and part is acquired largely through the sharing of toys and. other media with adults. More familiar is the way in which heavy objects teach us about gravity or the way a well-tuned sport car can give the driver a “feel” of the road which no passenger can ever share.

POSITION 3: Here the participants begin to lose the direct contact with each other’s reactions and they communicate more by effects which both produce upon a com­mon environment — although the effects themselves may be somewhat remote in space or delayed in their responsiveness. The referent is distinctly separate from the participants and their sharing of it might be termed ADJACENT.

Note, as we move from one position to the next, a number of other changes that are taking place. Direct reaction back from the medium becomes less important (e,g. a squeeze back from the hand that has been grasped light switches whose resistance to being moved is relevant to the status of the lights: on or off). Instead, the feed­back loops upon which a communicant depends In order to monitor the effects produced, become increasingly more reliant upon that part of the sensorium which we learn to use passively, at a distance: sight, hearing.

For the human participants there is a decreasing involvement of large-muscle movement: his efferent activity moving toward the fingertips and thence to lips and sign language where direct contact is unnecessary. As for the communicant’s problem of exploring the context, of his respondent’s messages, the need for more time of explora­tion and more storage of past experience for reference increases. Ambiguities become more difficult to resolve as they find expression simultaneously in more numerous sensorimotor modalities. Stated another way: expressions of intention are more equivocal because the recipient is less and less a part of the intender’s self-referent loops in his environment.

POSITION 4: At this distance the communication about the referent is METAPHORICAL in that its representa­tion is only mapped onto the environment of each partici­pant by implication. The model of the referent is not itself of real substance as it was in the preceding posi­tions in the sense that it could be manipulated directly, but rather the interaction must be brought about by an intervening agent. Chalk on a blackboard, a knob, push­button, or light-pen on a computer do not react back upon the user except to his eyes or ears. His participation, his Involvement in real events, has been reduced to a level where he can no longer have confidence in the reality of their source. E.g., the mayor no longer really knows how the statistics, gathered by others as a base for his decisions, were obtained; he does not participate in the intendings of the fact-finders.

POSITION 5: At the furthest distance shown we en­counter the familiar world of SYMBOLIC language and its referents which need not even exist in fact. This is the realm of the telegraph, high-speed printer, speechmaking, books, contract-writing, where the burden of the entailment of the intended meaning of a message rests almost entirely upon the sender’s mastery of the medium. I say ’’almost“ because in many cases the transaction be­tween participants can allow for some clarifying questions and answers.

Yet further, a sixth position on the scale might show a referent at the level of metalanguage of which this paper itself may be an example* Let us not continue the scale that far.

The proposed scale is intended to allow us to place in rank order the varieties of dialogue which we shall consider. The scale parameter has been referred to simply as ”distance“ in time and/or space, and although it may in fact be precisely quantifiable in many cases, for our pur­poses here it is quite sufficient to be able to specify a comparative ordering of a few examples. The primary focus of this paper is the broader speculation upon what other inferences may be made about a system and the dialogue in which it is engaged once its predominant position on the scale Is known. We have been able to extract a number of valuable design criteria from them.

A RECAPITULATION

It should be emphasized again that the communications of Interest here are those characteristic of dialogue and not those in which information flows In one direction only. If a system is intended to be employed simply as a filter M and does not allow the recipient an opportunity to be environment to the source, then a dialogue is not in process.The processes of dialogue are really fundamentally different from the more familiar ”scientific“ methods of telling or being told. Consider presenting to an engineer, trained in today’s state-of-the-art, the problem either of a communi­cation device to employ the receiver’s tactile sense or of a prosthetic hand for an amputee. Our best guess is that he will proceed immediately to think in terms of tailoring an input or an output characteristic as if either could valuably exist in Isolation. He will present tactile stimuli seriatim as patterns to a presumed passive recipient: making quite inappropriate use of a touching-grasping system which depends heavily upon freedom for exploration to achieve its highest-resolution ”sensing“. Dialogue design is needed. As for prosthetic hands, they have not yet been granted self-referent behaviors of their own[7] and are directed as simple inert tools, presenting feedback only to the user’s eyes. Neither engineered solution will be suited to the proposed scale because the referents are not describable in terms of the behavior of the systems selected to mediate them: those behaviors have in fact been made irrelevant.

A TABLE OF EXAMPLES

Table 1 presents four examples of application of the scale to different descriptive problems and is included for the purpose of convenient reference. The four are labelled respectively: Courtship, Architecture, Child Ontogeny, and Automobile Seat. They represent philosophi­cally: Human Communication, A Mode of Environmental Experi­encing, Human Developmental Learning, and a Man-Machine Interfacing Problem. Let us accept the simplification to compact word labels with a grain of salt. 

PROPERTIES OF AN ADEQUATE INTERFACE

Fig. 2 is an attempt at a simple schematic view of the increasing levels of system complexity that are required as one moves up the scale and as the pereelver’s task of modelling the referent becomes similarly more complex. Each diagram, numbered to correspond to the same respective scale positions in Fig. 1, is intended to depict one only of the two participants in the dialogue and to summarize graphically the relationships of the parts of the interfac­ing mechanisms to each other and to the referent. Each participant in the dialogue Is attempting to explore the referent to determine the intention [3] conveyed upon It by the other. Let me rephrase the foregoing sentence so that its meaning will not be obscure, for again the excep­tional properties of dialogue are such that its triadic[11] nature Is not revealed by our more familiar modes of desc­ription. If the referent were itself inanimate and were to be explored by a single observer, then there would arise no difficulty on the part of a second, passive obser­ver (wire-tapper, eavesdropper?) in bearing witness to the messages. However, if a dialogue is in process then the respondent is imposing intentionalities upon the referent which it did not possess before and which for their descrip­tion partake of the participation itself. One of the prob­lems upon which this paper is intended to shed light is that of placing some kind of upper bound on the complexity actually required for a realizable system engaged in a dialogue at various levels of the proposed scale. 

Consider that each instance of Fig, 2 represents the machine aspect of a man-machine interface.

Most of the work in which the author and his col­leagues are engaged at present is focussed on systems to be found at the lower end of the scales POSITION 1. Suppose, for example, one were to fashion a hospital bed which will participate with- the patient in manipulating him for ortho­pedic therapy: or suppose that an automobile seat were to be made that will concern itself with the comfort and alertness of the driver (i.e., the referent is the relation­ship of, between, and within the participants). It will be found that one needs no more complexity of computation within the mechanism than a simple reflexive responsiveness of each component to its own local environment, and. that this may in fact be provided within the structure of the components themselves. That is, as the physical relation­ships of the aggregate change, they thereby alter their own properties of responsiveness. Interactions between elements of the Interface will be effective but need not be explicitly provided as separate computations.

We have found that the liveliness of interaction of such a system with a human respondent is greatly enhanced if the interfacing mechanism is sufficiently sensitive to its own changes that it will sustain a slow, quasi-periodic movement of its own* not so slow as to be undiscernible (below respiration rates) but not so fast as to be alarming (above cardiac rhythms). While the device should not be preprogrammed to move, it should be mildly active even when the respondent is not. Of course, variations upon this self-generated activity produce a system which is even more useful, but It Is just such a self-adjusting variability that the next position offers.

Moving along to POSITION 2 of the scale, one might want to provide a means of ”holding hands at a distance“  or of communicating to a driver some of the conditions of his near surrounding (See Table 1)., The necessity arises for computations among the components of the Interfacing system which give them a behavior that is purposive in the aggregate. That is, the longer time-grain[2] and space-grain of its communications require that the organi­zing elements of the system be sensitive to the correlation of responses that are more separated in space or time than were those of Position 1. In our work it appears that multi-parameter, self-organizing controllers[1] will suffice and that their computations of performance assess­ment may be carried out in terms of the behavior of the component modules themselves; no additional sensorium is needed.

Further progression up the scale enriches the com­plexity of system realization. The immediate interactions, between the components of the interface and their environ­ment becomes less and less useful, but this is not to say that those interactions may be obviated for system function. Rather, it is to imply that the description of a receding referent becomes less relevant to the detailed interactions at the interface and that the performance assessment cri­teria of the system as a whole must be established by way of a more external, indirect means of observation. It may be seen that Fig. 1 and Fig, 2 show a similar progression. Each higher position should be viewed as an elaboration upon the one below it.

POSITIONS 4 and 5 correspond to ways in which com­puters are familiarly employed today. Respectively, com­puter graphics in architecture[12] is a recent example of man-machine ’’metaphorical’’ dialogue, and computer program­ming via compiler illustrates a symbolic exchange at a teletype. Let me state unequivocally that I DO NOT KNOW HOW to realize systems of hardware representative of Positions 4 and 5 if I go at it by my proposed approach: up the scale. Neither would I presume to name the evolu­tionary process so embodied ’’phylogenetic”. I do predict, 1 however, that the current interest in the development of \ small, locally dedicated computers can benefit from these considerations and that their own embodiments.will achieve their individual performance levels through a process of “ontogenetic” learning rather than by preprogramming. There is without doubt much value in the current state-of- the-art of computers and tremendous amounts of thought and capital have gone into their elaboration and refinement. They fall far short, however, of fulfilling a need for complex systems which can provide their skills to users who themselves have only informal means of communication: children in particular, but in addition a vast population of potential users who have tasks they want performed for which there exist, no .algorisms simply because In any Instance the user has not yet “decided” what It Is he wants. At present, the kinds of skills that human-beings develop easily are being made irrelevant by machines which cannot recognize their messages nor elicit their Intentions.

The major population for which we would like to see such efforts directed is that of the world’s children from age zero (literally) onward. In no other time In his­tory has It been so difficult for a child to raise the Information level of his own environment to where it responds to him in his style. The computer is looked, upon askance by most young students as just one more addition to an educational process designed to make them look stupid. My own contention is that this opinion can be reversed but / that it will take too long to achieve systems .of truly / dialogue design if one works down the scale from the top. There is the further, real danger that the embodiments arrived at would be far more complicated than necessary, ’

All along the scale there are simplicities to be exploited: it Is my hope that the scale itself will help to identify them.

The author gratefully acknowledges the criticisms and helps of his colleague, Warren M. Brodey, not only in the preparation of this paper but in they years of work leading to it.