In this paper, the authors examine two aspects of the acquisition of skills: how performance in a complex skill such as driving can be measured, and the relationship between changes in performance and amount of practice. In simple laboratory tasks these questions can be resolved in fairly objective and satisfactory ways. For example the index of performance is almost always based on number of incorrect responses and/or response time, and the relationship between practice and performance can be reliably derived when practice periods are treated as independent variables, and thus directly manipulated, within the experimental design. Where the skills under investigation are complex, and particularly where they are acquired in poorly controlled settings, the issues of indexing performance and of establishing the relationship with practice are less easily resolved. The authors go on to describe a study which provided data from a sample of learner drivers. As they progressed from being unable to drive to licensed driver status, each individual's performance was regularly assessed and measures of error and level of instruction are recorded. Each L-driver maintained a detailed record of all their driving experiences, and no restrictions were placed on the amount, type or frequency of driving. They conclude that whether time or distance are used as measures of experience, and whether ability is indexed as either number of errors committed or amount of instruction provided, driving skill develops as a power function of practice. (A)
Samenvatting