Preliminary Draft Outline


Douglas C. Engelbart December 13, 1961





It is proposed to develop equipment and techniques for providing preprogrammed tactile stimuli for subjects learning psychomotor skills. These stimuli would be provided in such a way that the subject is guided through the coordinated sequences of primitive actions that compose the desired skill actionswith the objective of increasing speed and effectiveness of training. It is desired to develop means to monitor a subject's performance, and to make decisions (both automatic and with humancoach interaction) which alter the guiding stimuli in ways that adjust to the subject's performance changes during the learning process.

It is planned to establish basic feasibility and gain initial experience and evaluation relative to these techniques by applying them to a simple keyboard-operation training task. This first phase would involve relatively simple equipment, and should fairly well establish the relative efficiency in learning rate, achievementlevel attainment, transference to onthejob proficiency, and retentivity provided by the new techniques, as compared with other training procedures.

Depending upon the results of the firstphase research, a specially designed research facility for automated psychomotor skill training is recommended. This facility would provide means not only for basic research into skilltraining questions and possibilities, but also for practical developments of automated training techniques for particular reallife skills.



Douglas C. Engelbart December 13, 1961

It seems reasonably probable that the proposed techniques could evolve into a training methodology that would not only reduce the time and cost of training people to given levels of proficiency in many areas of human activity, from simple keyboard operation to highlevel controlling and procedural tasks such as piloting a vehicle, but that would also raise significantly the humanskill levels upon which we could base the design of our tasks and equipment.


In learning, a coordinate physical skill now, the subject first has to memorize the reaction patterns associated with each primary stimulus involved in the skill. He needs to do this so that he can condition his automatic reactions to the stimulus by directing his body through the appropriate coordinated sequence of primitive actions whenever this primary stimulus is present. Other than his own memory, a subject learning a coordinate physical skill today generally has no mechanism to guide his association of the desired physical response with the stimulus. Also, he is not skilled in interpreting where his reactions went wrong; his own procedural feedback and unskilled guidance is clumsy, and is limited by his highercenter capability for remembering what should be done, and at the same time consciously controlling his body, monitoring its performance, and establishing corrective changes in his mental and physical processes. A human coach, observing the subject's progress, can help considerably in suggesting changes in his way of doing things, but these changes still have to be envisioned accurately by the subject and integrated into his other conscious controlling activity by highercenter processes. Also, there is often a problem due to the limitations in the communication means by which the coach can give corrective guidance during realistic practice. Where action is quite complex, the coach can only "describe" the changes that should be made, and let the subject try to incorporate these changes in succeeding practice trials, within the limits of his own interpretation and conscious controlling capability.

Our notion here is to relieve the load on the subject's highercenter faculties by means of "cueing" signals, applied cutaneously at judicious points



Douglas C. Engelbart December 13, l961

on his body, to guide him through his practice motions. This should remove the need for his memorizing the details of the reactions to which his automatic system is to be conditioned. Also, this should provide an improved communication means by which a coach (human) electronic, or combination thereof) can introduce detailed prompting and corrective information during the actual practice activity, to allow a much refined coaching process.

It is planned to achieve this by using signals from tactile stimulators, controlled generally by electronic means, to provide action cues to the subject. Each of these signals is initially to be associated in the subject's mind with one of the primitiveaction components that compose the physical action of the skill to be learned. The nature and location of each cue stimulus will be chosen to make as "natural" as possible its association with the primitive action which it is supposed to prompt. Using the typewriter for a very simple example, let us say that when the subject is to strike the letter "j" he will receive a shock or a buzz on his right index finger. Thus, instead of having to associate mentally the symbol "j" with the proper response, that of striking with his right index finger, he will receive an action cue on that finger to "show" him how to respond.

Reflex actions might possibly, by used to advantage for cueing, but this may not be generally convenient, and some of the primitive actions might be less suited to reflex cueing than to learnedresponse cueing. In any event, we assume that the subject will require a certain amount of preconditioning as to the particular primitive actions that are to be associated with each cue signal. The signals might be either mechanical or electrical (i.e., vibration, pressure, or electrical current) and perhaps sloweracting thermal signals would be of use on occasion, too.

As a more specific example, consider teaching the operation of the fivekey binary keyset discussed in the December 12 write-up on the ManMachine Communications. Here, the primary stimulus would be the presentation (probably visual) of a given alphanumeric symbol, and the skill response is to be the



Douglas C. Engelbart December 13, 1961

automatic depression of the appropriate combination of five keys that represents the binary code for that symbol. Means for providing a cueing signal to each finger are controlled by a programming device which is coordinated with primary-stimuli symbol presentation, and with the subjects response thereto. He is preconditioned to these cue signals (in this case, a fairly trivial matter) so that he associates each cue signal with the striking of a particular finger on its key. After the simple stimulusresponse reactions to the cueing signals are learned, the cueing signals could then be presented along with the primary alphanumeric code symbols, thus teaching the subject automatically to associate a particular alphanumeric symbol with the depression of a particular set of keys. There are many subtle variations to the way in which primary stimuli, subject response, and cue signals can be interdependent. A straightforward program would provide prompting to the subject, after presenting him with each primary stimulus symbol, to guide his responses. He would not have to memorize the alphanumeric code beforehand, nor hesitate overlong before determining what the correct response should be. Monitoring of the subject's progress can allow modification of the cueing process (e.g., diminishing cue signal strength, delaying cue signals, or skipping cues for some symbols) and the rate and sequence with which he is introduced to new primarystimuli symbols, to match the growth of his skill.

For more complex skills, cues may need to indicate more than just whether a limb in to move (i.e., direction and velocity may have to be indicated, too). A next higher level of skills might be such as typing, where cue signals not only prompt selection of a given finger, but also the selection of one of several alternative keys for that finger to strike. Here, for instance, a cue signal at the base of the finger might prompt that finger to strike the home key. If accompanied, however, by a signal on the "top" of the finger, say halfway to the end, the signal prompts the striking of the next key up from home position. Similarly, if the accompanying signal is on the "bottom" or "inside" of the finger, the cue prompts the striking of the key below home position. Other cuesignal locations on the finger or hand could provide other modifying information to guide the selected finger. Preconditioning here would take a little longer than it would with the fivekey binary keyboard.



Douglas C. Engelbart December 13, 1961

A next higher level of skill might involve the simultaneous coordination of several different primitive motions. Here the relative timing of the cueing signals gains a new importance. Here also we are beginning to benefit more from the "new communication means to the subject" than we were in the simpler skills. When an activity becomes a more complex coordination of primitive actions, it becomes increasingly hard to communicate to the subject, by ordinary means, just what is expected of him. The multichannel cuesignal system should make it much easier to communicate this type of information to the subjectand in a consistent form to which the subject might well develop automatic primitive responses.

This latter concept, the learning of automatic primitive responses to the cue signals so that a subject can be guided through complex responses with little demand upon this highercenter facilities, can be extended further. It could probably be that very complex skills can best be taught in stages, where the first stage involves the conditioning to respond to a firstlevel set of cues with a firstlevel set of primitive responses. The second level of training would use these cues to guide the conditioning to respond to a set of secondlevel stimuli with a set of secondlevel responses, composed each of coordinated combinations of firstlevel (primitive) responses. A third level of training would use the secondlevel stimuli as cues in guiding the conditioning to a set of thirdlevel stimuli with a set of thirdlevel responses, composed each of coordinated combinations of secondlevel responses, etc.

The degree of sophistication of the monitoring and control system, the selection of cueing signals, the complexity of the skills for which automated training is attempted, and the degree of skill to which a subject might be trained, seem from our present stage of trainingmethod development to be practically boundless.



Douglas C. Engelbart December 13, 1961


A. A Starting Point

A reasonably good test of the basic concepts of cuesignal prompting could be centered around a fivekey binary keyset. As mentioned above, the cueing need not be too sophisticated, since each cue signal need only tell a finger whether or not it is one of those which should strike its key in response to the associated primary stimulus symbol. Skill development should be smoothly measureable by reasonably simple means, so that relative progress of different trainees by different training methods would be easily obtainable.

A quite adequate teachingmachine system should be built up rather easily. A commercially available punchedpapertape reader could provide the preprogrammed controlling of cue signal transducers and keyactuationresponse checking. The subject could be reading an open text equivalent of the practice string of symbols punched on the tape, and the tape reader would pace itself automatically to his rate of "typing." Many variations in procedure would easily be available with quite simple controlling circuitry. For instance, when the subject is ready to go on a given string of symbols, he pushes a start button, whereupon he experiences a set of cue signals that prompt him to strike the code for the first symbol. When he strikes the keyboard with the correct key combination, the tape reader advances automatically, and he is provided with the cue signals for the second symbol, etc. If he should strike the wrong key combination at any time, an error signal (light, buzzer, or even a special signal of the same sort as the cue signals) would be energized, and the tape reader would notadvance to the next symbol until the proper code was struck on the keyset.

After the subject had begun to learn the correct responses, an adjustable delay period could be introduced, after each correct response and before the next cue signals were applied, to give the subject a chance to produce the correct response on his own before he is prompted. Or, the cue signal for the succeeding symbol could start at a subthreshold level immediately after the



Douglas C. Engelbart December 13, 1961

preceding correct response, and build up gradually. These variations are mentioned to bring out some of the possibilities than can enter into the experimentation. There are many others.

Instrumentation to provide automatic measurement of specific aspects of skill development would be fairly simple to attach to the equipment described above. Response time for keying entire symbol strings, or for particular symbols, could be indicated or recorded automatically, as could the number of errors over a given string of symbols of a given time, or the specific nature of the errors. This could help considerable, in measuring relative effectiveness of variations in training technique.

It would probably be worthwhile to utilize a Flexowriter, Teletypewriter, or other commercially available electricalinput typewriter. This would allow subjects once in a while to exercise their skill in a more directly rewarding manner, by typing out their exercise passages, with or without prompting.

The objective of the above described activity would be to get a reasonable measure of the relative effectiveness of the cuesignal prompting technique for the teaching of psychomotor skills. If these new techniques prove relatively ineffective, we might be impelled to find out why in continuing research. If they prove to be promising, the research can be extended both into the development of useful practical implementations for different kinds of skill, and into possible further development of the theory of learning to accomodate the findings of this research.

B. Further Work

1. General Experimental Facilities

If the basic techniques prove promising enough to warrant their extension into more sophisticated types of skill training and learningtheory study, it would seem most wise to spend additional effort at the outset in developing general facilities for further experimentation. The heart of the experimental



Douglas C. Engelbart December 13, 1961

facilities would be the equipment which controls the application of the cueing signals, programs the primary stimuli, measures detailed performance of the subject, perhaps modifies procedures automatically according to the measures of performance, and perhaps automatically processes the performance measurements to establish meaningful records of the subject's training history and progress. Peripheral to this, for different skilltraining situation would be the particular array of cuesignal transducers, the primarystimuli "transducers" or display, the operational facilities associated with practicing (or training) that skill, and the transducers (measuring devices) that convert performance features into signals useable by the controlling equipment.

There would be several possible approaches to building up such a testing facility, where provisions must be made for changing flexibly from one kind of procedural arrangement to another (and where the specific needs undoubtedly) can't be completely anticipated). On the one hand, one could develop special purpose switching and control equipment that incorporates enough special features to make it reasonably adaptable. This would not be inexpensive. On the other hand, one could build up experimental facilities around a small, general purpose digital computer, which could provide all the services of control and modification of detailed experimental procedures as well as performancedata analysis and record keeping. Each new kind of experimental setup then would require new development for only the practiceoperation facilities, the signal and monitoring transducers, and the computer program. One computer could be shared among any number of such setups (probably handling only one experiment in realtime operation at once), and would provide a maximum of allround experimental flexibility. It seems that if serious pursuit of automated skill training is to be undertaken, the development of experimental facilities around a computer should be given very serious consideration.

(NOTE: The computer facility that is planned at SRI for the Human Effectiveness Program would be ideal for such use.)



Douglas C. Engelbart December 13, 1961

2. Cue Stimuli Research

The nature of the physical stimuli to be used for cueing signals under different training situations would need some specific research attention. This would have to be coordinated with research on the possibilities for transducers that could convert the controlling electrical signals into the particular physical stimuli being considered. Some cueing signals have to be energized and elicit reaction in a very short time, which would tend to rule out chemical and thermal types of cutaneous excitation. However, these may prove useful for situations where speed is not important. Electrical currents would perhaps be the most convenient from an equipmentimplementation point of view, but they sometimes produce unpleasant sensations which might negatively affect the learning process. Research on cuesignal realization methods should begin soon after a decision is made to pursue cueprompted training automation in a serious manner.