Overview of the Papers: Why is Linear Thinking so Dominant?

A remarkable feature of the set of papers in this issue is the consistent pattern of tending to deal with non-linear situations as if they are linear that is shown by students widely differing in age and educational systems, and studying various topics within mathematics. Methodological issues about the difficulty of interpretation of student behavior, and the need to avoid attributing more rationality than is warranted, are raised. Suggestions about educational steps that could be taken to avoid an over-dependence on linearity are made. [ABSTRACT FROM AUTHOR]