Gordon Pask

It seems to me that the notion of machine that was current in the course of the Industrial Revolution—and which we might have inherited—is a notion, essentially, of a machine without goal, it had no goal ‘of’, it had a goal ‘for’. And this gradually developed into the notion of machines with goals ‘of’, like thermostats, which I might begin to object to because they might compete with me. Now we’ve got the notion of a machine with an underspecified goal, the system that evolves. This is a new notion, nothing like the notion of machines that was current in the Industrial Revolution, absolutely nothing like it. It is, if you like, a much more biological notion, maybe I’m wrong to call such a thing a machine; I gave that label to it because I like to realize things as artifacts, but you might not call the system a machine, you might call it something else.
Gordon Pask

Gordon Pask (1928-1996)
Gordon Pask (1928-1996)

At the beginning of 1956, two young Cambridge scientists, the psychologist Gordon Pask (1928-1996) and physicist Robin McKinnon-Wood (1931-1995), created a hybrid teaching and learning analog computer, in response to a request by the Solartron Electronic Group for a machine to exhibit at the Physical Society Exhibition in London.

Gordon Pask was an English scientist, designer, researcher, academic, playwright, and one of the early proponents and practitioners of cybernetics, the study of control and communication in goal-driven systems of animals and machines. Originally trained as a mining engineer, he went on to complete his doctorate in psychology. His particular contribution was a formulation of second-order cybernetics as a framework that accounts for observers, conversations, and participants in cybernetic systems.

The operation of the machine, called Eucrates (after the archon of ancient Athens from the 6th century BC, who was famed for neglect and excuses) was based on simulating the functioning of neurons. It was an embodiment of a conversation between machines, where one machine literally “teaches” the other. Let’s see the description of Eucrates, which appeared in the Monday, 4 June 1956, issue of TIME Magazine, London.

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A schoolteacher who is tireless, vigilant and indifferent to big red apples was on exhibit at London’s Physical Society. The teacher is electronic and the creation of two young Cambridge scientists, Physicist McKinnon-Wood and Psychologist Gordon Pask, under contract with Solartron Electronic Group Ltd. Designed for teaching such routine skills as typing and running radar equipment, the electronic teacher gives patient, individual attention.

October 1956: British scientist Gordon Pask co-inventor of an electronic brain used as a teaching aid called Eucrates I. (Photo by Harry Kerr/BIPs/Getty Images)
October 1956: British scientist Gordon Pask co-inventor of an electronic brain used as a teaching aid called Eucrates I. (Photo by Harry Kerr/BIPs/Getty Images)

The trouble with human teachers, say Wood and Pask, is that unless they are extremely good, they cannot observe in detail the intimate characteristics of each pupil. Each pupil’s biases, habits and individual eccentricities determine how he should be taught. He may favor his left hand over his right hand, or be able to remember odd numbers better than even ones. An ideal teacher should take all such matters into account and teach accordingly.

Solartron’s electronic teacher is set up to teach how to duplicate patterns of light in a frame containing eight lights. It starts the lessons by showing a single light. In another frame another light appears, telling the pupil which button to press. After a few such easy examples, the lessons get harder. Light patterns can be duplicated only by complicated operations with the buttons. The teacher gives clues, tells the pupil whether he is doing well or badly and makes him repeat over and over if he is making errors. Always understanding, the machine holds back a difficult exercise until the pupil is ready. If set up to teach typing, it can tell the pupil which finger to use and in which direction to move it. If the pupil is a hardened hunt-and-peck typist, the teacher will discover his sloppy habits and set about correcting them at once.

Wood and Pask got so interested in the teaching problem that they created an electronic pupil named Eucrates I, to give the electronic teacher a real workout. Eucrates is electronic but not bright. When not being taught, he is “thinking” in a confused way, and the electronic teacher must take account of his thinking habits. Eucrates follows instructions and observes clues, but is often wrong. If the teacher is too severe or goes too fast, Eucrates shows signs of electronic emotion, equivalent to bursting into tears. Then the electronic teacher is gentle with him until his little dials have stopped quivering.

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Solartron EUCRATES II, ca. 1956
Solartron EUCRATES II, ca. 1956

Later in 1956, Park and Wood invented Self-Adaptive Keyboard Instructor (SAKI), a machine, that adapts to the learner’s performance level (it was essentially a system for teaching people how to increase speed and accuracy in typing alphabetic and numeric symbols using a 12-key keyboard.) In late 1956, Park and Wood also created an improved version of Eucrates, called (surprise!) Solartron EUCRATES II.

In his book “An Approach to Cybernetics” (1961) Gordon Pask presents “learning machines”. Pask designates “Eucrates” as “simulating a pupil-teacher system”. The model reconstructs the behavior of “real neurons” and their “absolute refractory period”. The reactions of the “motor-elements” to the input are varying because of a shifting threshold: The threshold increases after the first input with the consequence for learners that they have to wait with further inputs until the threshold falls. “Memory-elements” react to the output of the “motor-elements”. The “memory-elements” are constructed following the example of “the synaptic connections of a neuron”: “Now it is obvious that various modes of activity and various forms of interaction [between a pupil and a teacher or the learning machine] will build up the network.” Pask writes this sentence after a short explanation of possible “interconnections” between “motor-elements” and the learning activities within the “network”. Capable of surviving within the “network” are only the connections that “mediate a favorable behavior”.