Defining Rectangle

When people know a word, their ability to define the word, or describe how they identify something as being that, is locked inside their brain. They think it is easy to get out, but usually it is not.

So, the task of defining a word is a good exercise in tinkering. People can usually come up with an initial definition. If they know how to check that definition, they can produce a better definition.

This is an enormously useful skill. Essentially, it is what experts should do when they try to teach their skills to others. You can use the same process to identify your feelings, and Gendlin claims that being able to identify your feelings is one of the keys to mental health.

It comes up in teaching math. It is useful to have people try to define common concepts in mathematics, as a way of learning about those concepts. Of course, to do that implies that students either have the ability to tinker. More plausibly, the teacher has to direct them in the tinkering process. But it helps if they appreciate tinkering. If they don't, they will view the process from a right-wrong perspective, where they are always wrong. Exercise. One of my standard exercises is to have people (or a class) try to define geometrical concepts. For whatever reason, I usually start with "rectangle". That tends to be difficult for most people. The only problem with this is that people do not know how to critique the definition that they construct first. It seems right, so they are happy with their answer. So you have to do the critiquing. If the students had the underlying concept of tinkering, and if they appreciated tinkering, that would work fine. Without that underlying concept, they tend to see your efforts as being critical, and that they can't get the answer right. The following is a "wrapper" for doing the define-a-rectangle exercise. The second-grader liked faeries. So I got a call from the faeries. (I had a telephone with me as a prop.) They were building something, following instructions, but they didn't know what a rectangle was. They didn't want my answer, they only trusted her (my second-grader). She gave her answer, which is a good exercise just by itself, and we called the faeries back and told them the answer. Then we were about to start our regular lesson when... the phone rang. They had constructed a rectangle, and they wanted to know if it was right. I drew it for my second-grader. As fate would have it, the figure fit her definition, but it wasn't a rectangle. So she had to construct a new definition. And then we were going to start our lesson when...the phone rang again. And so it went, for maybe 30 minutes. There was a faerie named Chuckles who always seemed to get things wrong and seemed especially troublesome and argumentative. The faerie named Glimmer was much more reasonable, but she sometimes had good questions. When I try this for fifth-graders, I think I will get a call from some aliens building a space-ship. I think this exercise is described elsewhere on my website. You have to be creative and think quickly if you get an odd definition. Your problem is to think of a shape that fits the definition but isn't a rectangle. It is also possible that the definition will become too restrictive, and then you need to realize that there is a shape that is a rectangle but doesn't fit the definition. But it also helps to have worked out the counterexamples for the most likely definitions: A rectangle is a four-sided figure. Show them an irregular quadralateral. A four sided figure where two sides are the same length and the other two sides are also the same length. Show them a diamond, where two adjacent sides are the same length and the other two (adjacent) sides are also the same length. A four sided figure with two opposite sides the same length and the two other opposite sides are the same length. (Any rhombus fits this definition -- the angles do not have to be 90 degrees.) If they mention that the two sides are bigger than the top and bottom sides -- turn the rectangle 90 degrees. If they include square in their definition -- I think that's okay, that a square is a rectangle. But they will usually try to exclude the square, and that's okay too. If they say the square has four sides and four angles (or four sides and four points), ask about shapes with four sides and five angles. If they have not specified straight lines, the lines of the figure can be curves. Perhaps you can even cross the lines. An hour-glass of two triangles would fit many definitions of rectangle. If they specify 4 right angles, I think they have the correct definition. If you have a lot of time left to fill in the session, the faeries might want to know what a right angle is.

Exercise: Defining Tinkering

Exercise: Testing

Tinkering Intro