This paper demonstrates a method for constructing long variables using items that elicit partically correct responses across ages. Long variables may be defined by students at different ages (year levels) attempting common items within a test containing other items considered to be appropriate for each age or year level. A developmental model of…

Investigates effects of an independent variable (grade) on three dependent variables (membership, partial association, and generalization) describing preferential styles of thinking in 1635 pupils, measured by a 16 concept word test. (DS)