A situated schema of proportionality.

The studies reported here are aimed at: (1) investigating the ability of fishermen with low levels of schooling to invert the everyday schema of proportionality; (2) investigating their ability to transfer the schema to another problem content; and (3) comparing their performance with that displayed by students of the same community who had been instructed on division and proportions, a comparison which may contribute to our understanding of the interplay between development and instruction.