Changing Minds Computers Learning and Literacy Andrea A diSessa A Bradford Book The MIT Press Cambridge Massachusetts London England 5 Intuition and Activity Elaborated The previous chapter introduced some fundamental perspectives on knowledge and learning Through the lenses of intuitive knowledge and the structure of activities and engagement I hope my images of future computational literacies appear both more plausible and more desirable Intuition and activity are extraordinarily rich topics and we continue to explore them in this chapter Doing so will be valuable for both skeptics and for enthusiasts Intuition Revisited Intuitive knowledge is not completely absent from cognitive research In fact much of my own research and that of a substantial bunch of colleagues has been directed toward understanding this form of knowledge This section briefly reviews some well developed ideas within this research and more expansively compares intuitive knowledge with some more familiar forms I want to contrast the use of a particular form of intuitive knowledge with the use of logic and word concepts in reasoning First I have to introduce and explain what a p prim is Would you be surprised in the following situation Suppose you were pushing an object along say a wheelbarrow full of grass cuttings in your yard and you decided to get the job done more quickly Naturally you push harder in order to go faster but in this case the wheelbarrow slows down and it slows down more the harder you push If someone told you a story about such an event you wouldn t believe it or you d say it had to be a trick and something was peculiar about this wheelbarrow How about the following similar scenario you are pushing your wheelbarrow around this 90 Chapter 5 time collecting rocks for a rock garden that you intend to build but every time you put a new rock in the wheelbarrow it got easier to push I believe that there is a particular element of intuitive knowledge what I call a p prim behind your surprise in these hypothetical situations In fact it is the first p prim I discovered and it turns out that it is among the more prominent and important p prims I call it Ohm s p prim and it works like this Whenever you see effort being expended to accomplish a task you expect a particular relationship between effort and result More effort begets more result That is the core of Ohm s p prim In addition however you know that there is always some kind of resistance involved in accomplishing a task In pushing things around that resistance depends on a number of things but everyone knows that heavier things offer more resistance That s the other part of Ohm s p prim More resistance begets less result or the reverse less resistance begets more result Here s my favorite example of Ohm s p prim Suppose you have a running vacuum cleaner and you put your hand over the nozzle Will the pitch of the motor which corresponds directly to its speed go up or down Many people will say that it must go down Implicitly they are saying that if you interfere or add resistance to a situation without compensating with an increase in effort you must get less result so the fan in the vacuum cleaner will spin slower The case of the vacuum cleaner is striking precisely because Ohm s pprim doesn t work Increasing the resistance by putting your hand over the nozzle actually makes the fan spin faster The pitch of the sound goes up Interestingly people preserve their belief in Ohm s p prim even in the face of exceptions If they know or see that the pitch goes up they say the vacuum must be working harder to overcome an increased resistance Ohm s p prim is a powerful and very general piece of intuitive knowledge Nobody can get along in the world without learning some version of it It applies to all sorts of situations where you push pull or in any other way interact in the world to accomplish something Ohm s p prim is not at all subtle You can feel resistance whenever you try to move things and there are very few exceptions to this regularity in the world Even more Ohm s p prim is not limited to physical situations People think metaphorically about their interactions with other people via this Intuition and Activity Elaborated 91 p prim I put metaphorically in quotes because it is not clear whether the physical world is a metaphor for the social world or the reverse I suspect neither is a good description but we simply learn in a wide range of circumstances that more effort begets more results We have to try harder to overcome the resistance of someone to an argument we are making The volume of your voice goes up in an argument as if you were turning up the voltage or pressing on the accelerator to make the engine work harder to make the car go faster What do you suppose people mean and what do they expect when they say we try harder I gave this intuition more effort more result more resistance less resultthe name Ohm s p prim because it very much resembles Ohm s law in electricity Ohm s law says that if you increase the voltage you get more current and if you increase the resistance in a circuit without a corresponding increase in voltage then the current decreases Ohm s law is easy to learn I believe because people see it naturally as a simple example of Ohm s p prim In general the term p prim refers to a class of simple little pieces of intuitive knowledge such as Ohm s p prim It actually stands for phenomenological primitive That s a mouthful but it is really quite descriptive The first part phenomenological means that p prims are evident in our experience of the world Many aspects of our experience are precisely the recognition of the p prim sense that the world makes We perceive phenomena through p prims and those phenomena are sensible to us because of that The primitive part is just as important First it means we can t take these p prims apart and say why they work Why do things move faster if you push harder There s no way to answer that question Our attitude is that s just the way things are P prims like any knowledge are not always correct If they did always work there wouldn t be any need for physics Instead sometimes they don t apply when we think they might In those cases we are surprised But when the p prims we see do work our attitude is nonchalant of course Because p prims are usually taken to be obvious and self explanatory people seldom mention them explicitly in explanations You don t say Johnny got bad grades because a he