ABSTRACT
The long history of categorization as a topic of intellectual curiosity and scientific investigation is in keeping with the important role that it plays in our everyday lives. The oldest theory of human categorization, known as the Classical Theory, dates back to Aristotle. The Classical Theory assumes that a category can be represented as a set of necessary and sufficient conditions (e.g., Bruner, Goodnow, & Austin, 1956; Smith & Medin, 1981). Therefore, the categorization process is a matter of testing whether the object in question possesses each of these conditions. If it does, it is judged to be a member of the category. If any of the conditions are missing, it cannot be a member of the category. For example, an equilateral triangle: (a) is a closed figure, (b) has three sides, (c) has all sides of equal length, and (d) is constructed only of line segments. Any figure that has these four properties is an equilateral triangle, and every equilateral triangle has these four properties.
