Expertise

Expertise refers to the psychological processes that underlie the superior achievement of experts, who are typically defined as those who have acquired special skills in, or knowledge of, a particular subject through professional training and practical experience. The term expert has a long history that can be traced all the way back to the training of skilled craftsmen in the guilds of the Middle Ages. At that time most of the professional skills, such as shoemaking, tailoring, and weaving, were taught through an apprentice system, whereby adolescents worked for a master in return for being allowed to observe and learn the skills of the trade. When the apprentices had sufficiently learned the necessary skills enabling them to work independently, they often left the master and traveled around the country as journeymen to find work. This allowed them to further develop their skills until they had reached a level of understanding and mastery of their craft to attain expert status. Eventually they would have accumulated skills to produce master pieces, which would meet the quality standard set by masters in the guild, who would give them permission to set up their own shop and accept their own apprentices.

Over time, the terms master and expert have been extended and are today used to describe a wide range of highly experienced professionals, such as medical doctors, accountants, teachers, and scientists. Its usage has even been expanded to include any individual who has attained superior performance by instruction and extended practice, ranging from birdwatchers to pianists, golf players to chess players.

When elite ice skaters, chess players, and musicians demonstrate outstanding skill in public, their performance often looks extremely natural and surprisingly effortless. To the casual observer, these exhibitions appear so extraordinary that it seems unlikely that most other performers, regardless of the amount or type of training, will ever achieve similar performance levels. It is tempting to attribute these amazing achievements to the performer's unique innate talent, deemed necessary for such superior performance achievement. However, when scientists began measuring the experts' presumed superior powers of speed of thought, memory, and intelligence with psychometric tests, no general superiority was found; the demonstrated superiority was limited to particular types of stimuli and activities. For example, the superiority of the chess experts' memory was constrained to regular chess positions and did not generalize to other types of materials. Not even IQ could distinguish the chess masters among chess players nor the most successful and creative among artists and scientists. Recent reviews show that (a) measures of general intelligence do not reliably distinguish those who will succeed in a domain, (b) the superior performance [Page 333]of experts is often specific to a domain of activity and does not transfer outside their narrow area of expertise, and (c) individual differences between experts and less proficient individuals nearly always reflect attributes acquired by the experts during their lengthy training.

The pioneering research on the thought processes at the highest levels of performance studied expert and world-class chess players. To gain insight into differences in speed and structure of thinking, the chess players were instructed to think aloud while selecting the next move for unfamiliar chess positions. The world-class players did not differ from the less skilled players in the speed of their thoughts or the size of their basic memory capacity. The superior ability of the world-class players to generate better moves was based on their extensive experience and knowledge of patterns in chess. In the first formal theory of expertise, William G. Simon and Herbert A. Chase proposed that experts with extended experience learn a larger number of complex patterns and use these new patterns to store new knowledge about which actions should be taken in similar situations.

...