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One of the criticisms I get about my work is that it is too focused on education technology in the US. I typically hear this every December, when I publish my year-end review of the field. Although I recognize that Americans are prone to self-centeredness, I don’t purposefully overlook the rest of the world’s experiences out of any sense of nationalism. Rather, I believe that education technology is imagined, developed, and implemented in a particular context. And that context is shaped by a country’s school systems, educational policies, and larger social, economic, and political forces.

(I often say: if you want to write an annual ten-part series about how your country has experienced education technology, please do.)

As I’ve written previously, many histories of education technology have been written as though this context is irrelevant. They spend little time talking about what was happening in education (as an institution, for example). As such, new technologies seem to appear out of nowhere – a creation of a genius inventor, rather than a reflection some larger cultural forces.

Teaching Machines will be limited in its scope to a particular time period in a particular country – that is, to the mid–1920s thru the late 1960s in the US. I want to be able to contextualize the work of Sidney Pressey, B. F. Skinner, Norman Crowder, and others by addressing how their machines coincided with developments in educational psychology and standardized testing; how they were responses to changes in student demographics and to the launch of Sputnik; how these machines reflected a twentieth-century fascination with gadgetry and automation; how they were part of a much larger push by businesses to sell curriculum products to schools; how they underscored that most American of values, individualism, with their proponents calling for instruction to become more “individualized.”

Education technology is not solely an American story. But the one I’m writing will be.

There is (I think) one possible exception to the American setting and American cast of characters, and that’s the British cybernetician Gordon Pask.

Pask is frequently credited with developing the first adaptive teaching machine. In 1956 patented the device, which served as the basis for the self-adaptive keyboard instructor (SAKI), a machine that the theorist Stafford Beer described as “possibly the first truly cybernetic device (in the full sense) to rise above the status of a ‘toy’ and reach the market as a useful machine.”

The SAKI was designed to train people to use a Hollerith key punch, a manual device used to punch holes in cards used in turn for data processing. There was at the time quite a significant demand for keypunch operators – mostly women – as this was, until the 1970s, a common method for data entry.

Like many teaching machines (then and now), SAKI purported to function like a human tutor. But unlike earlier teaching machines, the adaptive component of Pask’s devices offers more than just an assessment of right or wrong: they identify and measure a student’s answers – accuracy, response time – and adjust the next question accordingly. That is, the difficulty of the questions are not pre-programmed or pre-ordained. As Pask wrote in a 1958 article “Electronic Keyboard Teaching Machines,”

The only meaning which can be given to ‘difficulty’ is something which this particular trainee finds difficult. There would be little point in building our own idea of difficulty into a teaching machine, and still less an average difficulty scale, for example, a scale obtained by averaging the results of a number of tests using this exercise material presented to different subjects. This average measure of difficulty might be perfectly valid on the average, but it would almost certainly never apply to a specified individual. In fact, even for the same individual, something deemed difficult at one moment will be rated easy the next.

Stafford Beer described using the SAKI in his 1959 book Cybernetics and Management:

You are confronted with a punch: it has blank keys, for this is a “touch typing” skill. Before you, connected to the punch, is Pask’s machine. Visible on it is a little window, and an array of red lights arranged like the punch’s keyboard. The figure “7” appears in the window. This is an instruction to you to press the “7” key. But you do not know which it is. Look at the array of lights. One is shining brightly: it gives you the position of the “7” key, which you now find and press. Another number appears in the window, another red light shines and so on. Gradually you become aware of the position of the figures on the keyboard, and therefore you become faster in your reactions. Meanwhile, the machine is measuring your responses, and building its own probabilistic model of your learning process. That “7,” for instance, you now go to straight away. But the “3,” for some obscure reason, always seems to elude you. The machine has detected this, and has built the facts into its model. And now, the outcome is being fed back to you. Numbers with which you have difficulty come up with increasing frequency in the otherwise random presentation of digits. They come up more slowly, too, as if to say: “Now take your time.” The numbers you find easy, on the contrary, come up much faster: the speed with which each number is thrown at you is a function of the state of your learning. So also is the red-light system. For as you learn where the “7” is, so does the red-light clue gradually fade. The teacher gives you less and less prompting. Before long, if you continue to improve on “7,” the clue light for “7” will not come on at all. It was getting fainter on ‘“5,” for you were getting to know that position. But now you have had a relapse: “5” is eluding you altogether. Your teacher notes your fresh mistakes. “5” is put before you with renewed deliberation, slowly; and the red light comes back again, brightly… . So the teaching continues. You pay little intellectual attention: you relax. The information circuit of this system of you-plus-machine flows through the diodes and condensers of the machine, through the punch, through your sensory nerves and back through your motor nerves, the punch, the machine. Feedback is constantly adjusting all the variables to reach a desired goal. In short, you are being conditioned. Soon the machine will abandon single digits as the target, and substitute short runs of digits, then longer runs. You know where all the keys are now; what you have to learn next are the patterns of successive keys, the rhythms of your own fingers.

Image credits: Gordon Pask, "SAKI: Twenty-five years of adaptive training into the microprocessor era"

As the patent application argues, the adaptivity of the machine serves to keep student’s interest:

If the operator is receiving data at too slow a rate, he is likely to become bored and attend to other irrelevant data.


If the data given indicates too precisely what responses the operator is required to make, the skill becomes too easy to perform and the operator again tends to become bored.


If the data given is too complicated or is given at too great a rate, the operator is unable to deal with it. He is then liable to become discouraged and lose interest in performing or learning the skill.


Ideally, for an operator to perform a skill efficiently, the data presented to him should always be of sufficient complexity to maintain his interest and maintain a competitive situation, but not so complex as to discourage the operator. Similarly these conditions should obtain at each stage of a learning process if it is to be efficient. A tutor teaching one pupil seeks to maintain just these conditions.

Pask argued that, by using the SAKI for 35 minutes every workday, a novice keypunch operator could be trained to type 7000 KDPH (key depressions per hour) in 4–5 weeks. “There is a slightly arcane figure (which is, however, if anything conservative),” he wrote in an article reviewing twenty-five years of SAKI development, “citing between 30% and 50% saving in training time.”

According to one source, the rights to manufacture SAKI were acquired from Pask’s company System Research by Cybernetic Developments in 1961; and only about 50 machines were sold. But I’ve come across several mentions of SAKI that indicate that Rheem Manufacturing also built and sold the device – and that’s of particular interest to me as Rheem also worked with B. F. Skinner to manufacture his teaching machine (a relationship that eventually fell apartment due to Skinner’s dissatisfaction with the direction Rheem – and, indeed, the field of teaching machines – was taking).

The trick, I suppose, will be making the British Pask not come off as an interloper in an otherwise American story.

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Audrey Watters


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Teaching Machines

A Hack Education Project

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