ABSTRACT
This chapter explores an emerging perspective on some promising, and challenging, areas in cognitive development, as well as in cognitively oriented instructional design realized by Bob Siegler and Klahr David. It presents a set of fundamental questions in the areas of development and instruction. The questions includes what are the differences in knowledge that underlie different levels of task performance? What are the alternative strategies that might result in any given level of task performance? What do children know about a task, how do they learn about it, and why do some know more and/or learn more than others? The chapter demonstrates that the rule assessment methodology was not limited to the balance scale, but could productively account for children's performance on an astonishingly wide range of classic Piagetian tasks: time, speed, distance, and projection of shadows, among others, as well as "CMU-type" puzzles and problem-solving tasks.
