The Development of Measurement Operations among the Oksapmin of Papua New Guinea.

SAXE, GEOFFREY B., and MOYLAN, THOMAS. The Development of Measurement Operations among the Oksapmin of Papua New Guinea. CHILD DEVELOPMENT, 1982, 53, 1242-1248. The purpose of this study is to analyze cognitive developmental changes in the use of a convention for measurement among the Oksapmin, a recently contacted cultural group who live in a remote section of Papua New Guinea. The Oksapmin measurement system consists of conventionally defined points on the arm and is used in practical activities involving the measurement of string bags, a common cultural artifact. The subjects consisted of 103 individuals, including unschooled children, unschooled adults, grade 2 children, and grade 6 adolescents, who were administered 3 types of tasks assessing their ability to use their conventional system to produce comparisons of lengths. These included tasks involving conservation of length, the comparison of 2 measurements produced by a subject, and the comparison of 2 measurements produced by 2 individuals of different sizes. A finding of particular interest was that the Oksapmin develop an understanding of the necessity of equivalent units despite the fact that units of measurement are not equivalent in the Oksapmin system since individuals' arms vary in length.