Describe and evaluate Siegler's model of strategy choice

What will be an ideal response?

Siegler's model of strategy choice uses an evolutionary metaphor—"natural selection"—to help us understand cognitive change. When given challenging problems, children generate a variety of strategies, testing the usefulness of each. With experience, some strategies are selected; they become more frequent and "survive." Others become less frequent and "die off." Like the evolution of physical traits, children's mental strategies display variation and selection, yielding adaptive problem-solving techniques—ones best suited to solving the problems at hand.
To study children's strategy use, Siegler used the microgenetic research design, presenting children with many problems over an extended time period. He found that children experiment with diverse strategies on many types of problems—basic math facts, numerical estimation, conservation, memory for lists of items, reading first words, telling time, spelling, and even tic-tac-toe.
Siegler found that strategy use for basic math facts—and many other types of problems—follows an overlapping-waves pattern. Performance tends to progress from a single incorrect approach, to a highly variable state in which children try different strategies, to use of a more advanced procedure.
Siegler's model reveals that no child thinks in just one way, even on a single task. A child given the same problem on two occasions often uses different approaches. Strategy variability is vital for devising new, more adaptive ways of thinking, which "evolve" through extensive experience with solving problems.