8 AISB Quarterly

Much of what we know about expertise comes from research into chess by de Groot in the forties and Chase and Simon in the seventies.1,2 Two classic de Groot results demonstrated the importance of perception in expert behaviour. First, even though grandmasters found better moves than strong amateurs in a problem-solving task, there were few differences in their search behaviour. In particular, all players were selective and visited only about one hundred positions. Second, chess masters performed almost perfectly in the recall of game positions (see Figure 1) presented for a few seconds. To explain these results, Chase and Simon developed the ‘chunking theory ’ that proposed mechanisms specifying ho