2. Tell the difference between learning and teaching? Explain what kind of learner are you?

50. What is pruning. It is this second stage of subsumption that operates through what I have called "cognitive pruning" procedures (Brown 1972). Pruning is the elimination of unnecessary clutter and a clearing of the way for more material to enter the cognitive field, in the same way that pruning a tree ultimately allows greater and fuller growth. Using the building-block analogy, one might say that, at the outset, a structure made of blocks is seen as a few individual blocks, but as "nucleation" begins to give the structure a perceived shape, some of the single blocks achieve less and less identity in their own right and become subsumed into the larger structure. Finally, the single blocks are lost to perception, or pruned out, to use the metaphor, and the total structure is perceived as a single whole without clearly defined parts.

An example of such pruning may be found in a child's learning of the concept of "hot"—that is, excessive heat capable of burning. A small child's first exposure to such heat may be either direct contact with or verbally mediated exposure to hot coffee, a pan of boiling water, a stove, an iron, a candle. That first exposure may be readily recalled for some time as the child maintains a meaningful association between a parent's hot coffee and hurting. After a number of exposures to things that are very hot, the child begins to form a concept of "hotness" by clustering experiences together and forming a generalization. In so doing the bits and pieces of experience that actually built the concept are slowly forgotten—pruned— in favor of the general concept that, in the years that follow, enables the child to extrapolate to future experiences and to avoid burning fingers on hot objects.