This study investigated, in the field, the effect on transfer of training of four different training methods. A ‘transfer module’ of one of four sorts for each trainee was added to training in micrometer use then, after a 13‐week lay‐off, training in vernier height‐gauge use was undertaken. The subjects were trainees on Youth Training Scheme construction courses. The results showed that subjects who received a transfer module consisting of exposition of the principle of vernier scales were more effectively trained to use vernier height‐gauges than subjects in all other groups. Subjects whose transfer module consisted of practical use of a wide variety of high‐accuracy measuring tools were more effectively trained to use a vernier height‐gauge than subjects in a control group who received no transfer module. Subjects whose training module was further practice with micrometers and those who learned about relationships between measuring tools, tasks, and jobs were no more effectively trained to use a vernier height‐guage than were control subjects. Results are discussed in terms of knowledge/action structures of memory which may be mecha