ABSTRACT
It is a broadly accepted assumption that human beings construct their knowledge by a continuous process of interaction between the individual's cognitive system and his/her physical and cultural environment. This chapter focuses on the question of how children construct specific knowledge about the concepts, solid and liquid, and how different content-related factors (experience, perception, language, etc. — see White, chapter 18 in this volume), or learner-related factors (age, instruction, etc.) affect this process. This is done with the belief that if we understand how children represent these concepts, how they construct their knowledge about them, and how the above-mentioned factors affect this process we should be able to improve our methods and timing and sequence of teaching them.
