A constraint on comparisons: Equally detailed alternatives

Children's errors in collective comparison tasks are atributed to the comparison of the wrong classes. It is specifically hypothesized that alternative classes are erroneously formed subject to the constrain that the same kinds of properties are criterial for each alternative. This hypothesis, called the equally detailed alternatives hypothesis, is tested in three experiments with hierarchically organized stimuli and requests to compare a superordinate class and a nonincluded subclass, for example, dogs and yellow cats. In all three experiments 4-year-old children's comparisons were found to be in accord with the hypothesis. In the first experiment both perceptual and linguistic factors determine which classes are compared. In the second experiment, as predicted, erroneous subclass comparisons were more common when all subclasses were distinguished by the same kinds of properties. In the third experiment, the children were asked to partition the stimulus objects into the classes to be compared. The vast majority of partitions were erroneous and in accord with the hypothesis. Potential benefits of the constrain are considered.     

On the adequacy of prototype theory as a theory of concepts

Prototype theory construes membership in a concept's extension as graded, determined by similarity to the concept's “best” exemplar (or by some other measure of central tendency). The present paper is concerned with the compatibility of this view of concept membership with two criteria of adequacy for theories of concepts. The first criterion concerns the relationship between complex concepts and their conceptual constituents. The second concerns the truth conditions for thoughts corresponding to simple inclusions.     

Distance estimation from cognitive maps

Four experiments investigated map clutter as a source of distortion in subjects' estimates of distance. In Experiments 1 (incidental learning) and 2 (intentional learning), subjects estimated distances between pairs of points on a memorized map. In both experiments, estimates increased as a linear function of the number of intervening points along the route. In Experiment 3, subjects estimated distances while viewing the map. The effect of clutter was reduced but not eliminated. In Experiment 4, the clutter effect was demonstrated using subjects' preexperimental knowledge of United States geography. Psychophysical power functions relating true to estimated distance provided a good fit to both memory and perception data. These results suggest an analogy between perceptual and memorial processes of distance estimation. A model proposed to account for the data assumes that subjects perceptually scan a route (or image of a route) from start to destination and use scan duration to determine path distance.     

Sex differences in retention of verbal and spatial characteristics of stimuli: A cross-cultural replication

This study is a partial (omitting college students) replication of R. V. Kail and A. W. Siegel (Journal of Experimental Child Psychology, 1977, 23, 341–347) in Ghana and Scotland on boys and girls with 4 and 7 years of education. After viewing sets of five or seven letters in a 4 × 4 matrix they remembered either (a) the letters, (b) positions of the letters, or (c) both letters and positions. Contrary to the results of the original study, no sex difference in relative recall of letters and positions was found. There was also evidence that verbal and spatial information is not always processed independently. A prediction that Scottish children would have better recall of positions was supported. The discussion notes the limitations of intracultural research as a basis for generalizations.     

Cognitive processes in person perception: Retrieval of personality trait and behavioral information

The processes people use to retrieve information about another person's behavior and personality were investigated. Subjects viewed different lengths of segments from videotaped sequences of actors' behaviors. The subjects' reaction times to questions about the actors' behaviors and about personality traits were both an increasing function of the duration of the segment about which the questions were asked. These data were taken as an indication that people do, in general, carefully examine the contents of their memories in order to respond to questions about another person. In particular, an exhaustive serial search model was supported. Additional data and analyses demonstrated that relatively abstract trait terms usually were answered on the basis of the exhaustive search, while relatively specific trait terms were not. A two-stage process model was proposed to explain the differences in the results for the two types of trait terms.