Abstract
Because of rapid social changes in preliterate societies,'body techniques'(in this study, clothes-making skills)that are passed down from generation to generation are in danger of disappearing. There are currently efforts at local vocational schools to develop practical training methods and curriculums to preserve traditional skills. To help these efforts, research is being done both on the tools and materials for clothes-making, and on a rational and effective system of instruction. In this study, 106 subjects were surveyed to determine whether they had acquired 34 carefully selected traditional clothes-making skills. For each skill, the average age of skill acquisition x and Item Response Theory-derived difficulty parameters(β) and discrimination parameters(α), were used to investigate the optimal timing for traditional skills instruction. We surveyed 106 Karen women in Chiang Mai Province, Thailand with clothes-making experience. For each skill, we sought the above-mentioned parameters(α)and(β), the average age of skill acquisition x,and the standard deviation(σ). Analysis of the indifference curves obtained from plotting(α),(β), and(σ)vs. x in a two-dimensional figure, clearly pointed to a solution for this optimization problem. We found out useful information about the optimal age for teaching each skill. Furthermore, we think that we can use this same method for similar optimization problems relating to the transmission of traditional skills.
