"Two dimensions of conceptulization, freedom and extensionality, were postulated; from these postulations, it was hypothesized that the type of conceptual behavior previously identified as concrete could be demonstrated to occur in two more or less mutually exclusive conceptual areas--hypostatic and autistatic. With the use of these constructs, two experimental groups were separated on the basis of consistent differences in concept formation in an object-sorting situation. The validity of this separation was tested by statistically evaluating the significance of predicted group differences in language behavior." Since significant differences were found in the direction predicted, it was concluded that "conceptual area might be a more useful concept for some purposes than conceptual level in that the latter term would not have supported such a prediction." (PsycINFO Database Record (c) 2006 APA, all rights reserved)