Importance of the overall similarity of objects of adults' and children's classifications

Previous work has shown that adults and older children tend to classify multi-dimensional objects by identity on one dimension, whereas children under 8 years of age tend to classify these same objects by a relation of overall similarity. The present study investigated the hypothesis that this developmental trend is restricted to the classification of simple objects that differ only by limited amounts on a few dimensions. The specific hypothesis was that overall-similarity relations structure both adults' and children's classifications of heterogenous objects (objects that differ in a variety of ways). This hypothesis was suggested by the correspondence between the structure of young children's classifications and the structure of natural categories. The result of two experiments supported the hypothesis. When the to-be-classified objects varied simultaneously on relatively many dimensions, adults as well as children constructed classifications that maximized within-category similarity on all varying dimensions. The implications of these results for accounts of the perception of multidimensional relations and classificatory behavior are discussed.     

Exploring and reexploring issues of integrality,perceptual sensitivity,and dimensional salience

Some observations that can be described conveniently by investigators in terms of dimensional sensitivity and dimensional salience actually need not implicate the psychological reality of the dimensions for the subjects. The developmental hypothesis that stimuli are perceived often as integral in early childhood can account for such phenomena only with the assumption that young children often apprehend objects as global wholes, related to one another by overall similarity. Classification data, recently presented by J. R. Aschkenasy and R. D. Odom (Journal of Experimental Child Psychology, 1982, 34, 435–448) can be reinterpreted in this way. On this reinterpretation, Aschkenasy and Odom's findings are exactly what the developmental form of the integrality-separability hypothesis predicts. Moreover, a variety of other findings and lines of inference converge on the conclusion that, in young children, the use of overall similarity relations to organize perception and cognition predominates over the use of dimensional relations (and that the relative balance between these stimulus relations changes in development). Examples are selected from the literature on the natural development of word meanings, as well as from the literatures on children's and adults' classification.     

Young children's attention to global magnitude: evidence from classification tasks

Young children often compare objects holistically and not in terms of separate dimensions such as size and color. One holistic relation that often governs young children's object comparisons is overall similarity. Two experiments were conducted to examine the possibility that a holistic magnitude relation might also govern children's object comparisons. Objects varying on two dimensions of magnitude-size and saturation--were classified by 3-, 4-, and 5-year-olds. The results indicated that the younger children were sensitive to global magnitude as well as overall similarity. They grouped together large and saturated objects or small and desaturated objects more often than they did large and desaturated (or small and saturated) objects and thus appear to have been classifying by combined magnitude across both dimensions. This new finding that young children classify by a global relation of magnitude refines the understanding of perceptual development and provides information about the structure of perception. Young children's use of global magnitudes in classification also fits well with recent findings about children's acquisitions of dimension words.     

Exploring the effects of similarity on mapping spatial relations

Solving a map task requires transferring information acquired in one spatial context to another context, an ability that marks an important step in cognitive development. This study investigated how preschoolers’ mapping performance was affected by the extent of similarity between spaces. Whereas prior work examined effects of similarity in tasks involving matching individual objects, our tasks required considering spatial relations among objects. We found that the accuracy of mapping between two spaces with somewhat different perceptual features was higher than the accuracy of mapping between spaces with identical features. Yet, a further increase in differences between the two spaces had a detrimental effect on mapping. The results suggest that some degree of similarity between spaces is beneficial to children’s ability to transfer relational information. However, when the spaces have the same surface features, it may draw children’s attention to individual objects and inhibit their ability to focus on common relations across contexts.     

The semantic deficit hypothesis: Perceptual parsing and object classification by aphasic patients

Many aphasic patients are impaired in their ability to provide or to recognize the names of objects, but little is known about the processing deficits that underlie these difficulties. In this report, a model of object naming/name recognition is proposed, and a prediction is tested concerning one possible functional locus of impairment in name-recognition and object-naming disorders. A subgroup of aphasic patients is found to be impaired in the ability to perform perceptual similarity judgments for pairs of stimulus objects, and to be unable to classify the objects into one of two lexical categories. It is concluded that the classification disorder suffered by these patients results from an impairment at the level of the semantically guided perceptual parsing of objects.     

Developmental differences in visual processing: strategy versus structure

The present study was an examination of two contrasting explanations for the finding that young children tend to classify objects according to similarity relations whereas adults emphasize dimensional structure. Subjects from three different age groups were given tasks that tapped different aspects of the visual process: Feature search, Conjunction search, and Restricted Classification tasks. In addition, three different stimulus objects (a highly separable, a highly integral, and an intermediate dimensional combination) were studied to explore the contribution of stimulus structure in dictating the nature of the processing mode. The results provided evidence against the view that children perceive objects according to a more primitive holistic structure. Rather, the results can be taken with past research to suggest that less efficient visual processing may lead the younger subjects to adopt a classification strategy that emphasizes similarity relations. In addition, the current research supported Garner's (1974, The processing of information and structure, Potomac, MD: Erlbaum) suggestion that the nature of the processing mode is stimulus-driven.     

Young children's discovery of spatial classification

Around the age of 18 months, children begin to classify objects spatially by kind, placing objects of the same kind close together in space and placing unlike objects apart. This behavior may be symbolic in the sense that children use spatial proximity to represent similarity. We examined the possibility that spatial classification is discovered during play—that the external products of play lead children to use space to represent similarity. Experiment 1 was a longitudinal study of four children's classification behaviors, observed from the age of 16 to 21 months. Results suggest that play with one kind of object to the exclusion of another kind leads to the discovery of spatial classification. Experiment 2 examined how children's tendencies to interact with one category might promote spatial classification of multiple categories. Twenty-four 18-month-old children who did not yet spatially classify objects by kind participated. Children who were given the experience of playing with two kinds of objects in a context that promoted interaction with only one kind were more likely to demonstrate spontaneous spatial classification of multiple kinds in a subsequent test period. Children who played equally with both kinds did not show heightened spontaneous classification. The results further suggest that comparison of different kinds during play is critical to the spontaneous occurrence of spatial classification.     

主题关系在4~5岁儿童不同属性归纳推理发展中的作用

为探讨主题关系在儿童归纳推理中的作用,采用经典的三角归纳范式,设计了主题关系和知觉相似冲突、主题关系和分类学关系冲突两种情形,来考察4~5岁儿童在内在属性和情境性属性任务中的归纳推理。结果显示：当主题关系和知觉相似冲突时,从4.5岁开始儿童主要基于主题关系对情境性属性进行归纳推理,而对于内在属性的推论,4~5岁儿童在基于主题关系和基于知觉相似上没有显著差异。当主题关系和分类学关系冲突时,从4.5岁开始儿童主要基于主题关系对情境性属性进行归纳推理,从5岁开始儿童主要基于分类学关系对内在属性进行归纳推理。两个实验结果均发现5岁和5.5岁儿童能够依据不同的属性使用不同的关系推理,表现出归纳灵活性     

Developmental trends in the use of perceptual and conceptual attributes in grouping,clustering, and retrieval

In Experiment I, two tasks were administered to children aged 4, 5, and 9 in order to investigate preference for perceptual versus conceptual attributes in grouping of common objects, and in various aspects of memory. The grouping task revealed a clear chronological progression: color and form determined the youngest children's grouping about equally; form dominated in the 5-year-olds; and most of the oldest children grouped primarily by conceptual attributes. In the memory task, three lists—one organized by color, one by form, one by superordinate category—were presented for free, followed by cued recall. Clustering showed the developmental shift from color to form to concept, while cued recall showed conceptual superiority at all ages. Experiment II replicated the memory task, yielding the same results. The results were discussed in terms of the relative abstractness and predictability of conceptual versus perceptual attributes and the difficulty of abstraction in encoding and the function of predictability in retrieval.     

Heuristics in learning classifiers: The acquisition of the classifier system and its implications for the nature of lexical acquisition

Classifiers are like nouns in that they classify entities in the world into lexical categories. However, the lexical nature of the classifier system is very different from that of nouns. We discuss how Japanese and Chinese children learn the meanings of classifiers. We focus on two specific questions: How classifier acquisition is different from noun acquisition; and what the prerequisites are for spontaneously extracting the meanings of classifiers. It is shown that children are very conservative in assigning meaning to classifiers. The pace of learning largely depends on semantic complexity, across languages and within each language. Furthermore, we suspect that learning the meanings of classifiers requires a certain cognitive ability – an ability to synthesize pieces of partial knowledge and form them into a cohesive whole. It may be only when children have developed such an ability that they are able to extract the complex semantic rules of classifiers on their own. We conclude that children take very different routes in learning nouns and classifiers: Unlike noun acquisition, classifier acquisition is guided by a slow, bottom-up process.     

Categorization by schema relations and perceptual similarity in 5-year-olds and adults: A study in vision and in audition

This research explores the way in which young children (5 years of age) and adults use perceptual and conceptual cues for categorizing objects processed by vision or by audition. Three experiments were carried out using forced-choice categorization tasks that allowed responses based on taxonomic relations (e.g., vehicles) or on schema category relations (e.g., vehicles that can be seen on the road). In Experiment 1 (visual modality), prominent responses based on conceptually close objects (e.g., objects included in a schema category) were observed. These responses were also favored when within-category objects were perceptually similar. In Experiment 2 (auditory modality), schema category responses depended on age and were influenced by both within- and between-category perceptual similarity relations. Experiment 3 examined whether these results could be explained in terms of sensory modality specializations or rather in terms of information processing constraints (sequential vs. simultaneous processing).     

Perceptual units in the acquisition of visual categories

A series of experiments provided evidence that the representational structure of categories comprising dot patterns is based on pattern parts and pattern configuration rather than on pattern elements. We found that similarity judgments and postacquisition classification data could not be explained in terms of element-level perceptual units, even for categories of dot patterns with seven of their eight dots in the exact same relative location. The importance of higher order perceptual units was indicated by evidence that the long-term retention of information specific to previously learned category exemplars, which is typical of natural objects, can also be obtained for artificial dot patterns, providing their structure reflects the perceptual characteristics identified in Tversky and Hemenway's (1984) study of natural objects: Members of the same category had to be perceptually distinctive at the level of pattern configuration and perceptually similar at the level of pattern parts. The level of within-category similarity for a set of categories (relative to between-categories similarity) did not predict whether item-specific information would be retained; long-term retention appears to require both within-category similarity and dissimilarity, but at different levels of perceptual structure.     

Bridging the gap: Causality-at-a-distance in children's categorization and inferences about internal properties

Previous research has shown that preschoolers extend labels and internal properties of objects based on those objects’ causal properties, even when the causal properties conflict with the objects’ perceptual appearance [Nazzi, T., & Gopnik, A. (2000). A shift in children's use of perceptual and causal cues to categorization. Developmental Science, 3, 389–396; Sobel, D. M., Yoachim, C. M., Gopnik, A., Meltzoff, A. N., & Blumenthal, E. J. (2007). The blicket within: Preschoolers’ inferences about insides and causes. Journal of Cognition and Development, 8, 159–182]. These studies, however, only presented causal relations that acted on contact. In two studies, contact causality was replaced by distance causality. In contrast to the contact causality case, 4- and 5-year-olds extended labels to objects with similar perceptual properties over objects with similar causal properties when those properties acted at a distance. When children were asked to make inferences about object's internal properties, they were more likely to make causal responses, with 5-year-olds doing so to a greater extent than 4-year-olds. In a second study, 4-year-olds registered causal properties that acted at a distance and used them to make inferences when no perceptual conflict was present. These results support a hypothesis that young children develop an understanding of the specific mechanisms that link causal relations.     

Classification behavior and measures of intelligence: dimensional identity versus overall similarity

Individuals tend to adopt either analytic or holistic modes of categorizing objects. In two studies, we examined the relation between these categorization tendencies and cognitive abilities as measured by standard psychometric instruments. The participants in both studies were pretested with a restricted classification task in which it was possible for them to classify simple stimuli by dimensional identity or overall similarity. Those making a large number of either type of categorization were then tested with subtests of the WAIS-R and with the Raven's progressive matrices. Across both studies, the analytic individuals (many dimensional identity classifications) scored higher than the holistic individuals (many overall similarity classifications) on some but not all of the subtests. The results are consistent with the idea that holistic modes of categorization may be more "primitive" than analytic modes. The findings are discussed in terms of the association between categorization mode and either general or specific cognitive abilities.     

Learning to Align Relations: The Effects of Feedback and Self-Explanation

Relational similarity connects superficially dissimilar objects and events. In 2 experiments, the ability to recognize and respond to similar relations was studied in children ages 3 to 5 with 2 comparison tasks. Children interpreted illustrated pictures that shared perceptual or relational aspects and then made 2 comparison choices and explanations of these choices. Results of Experiment 1 demonstrated that when given explicit feedback regarding the relations depicted in the pictures, children learned to respond quickly to this type of similarity in subsequent trials, which involved novel relations. In Experiment 2, the effect of re- explanation on relational understanding was examined. Children age 4.5 to 5 years, but not 3- to 4-year-olds, showed relational learning when asked to explain the experimenter's relational choice.     

Object manipulability affects children’s and adults’ conceptual processing

Research on kinds of concepts indicates that children use perceptual and functional information differently to form natural and artifact concepts. Beyond object domain, object manipulability appears to be a decisive factor in adult conceptual processing. Thus, the effect of object manipulability on conceptual processing was tested in 5- and 7-year-olds and adults using a picture matching task. Reaction times for identifying conceptual relations on the basis of perceptual similarity (e.g., jacket-coat) and contextual/functional information (e.g., jacket-hanger) were analyzed according to object manipulability and domain. Both children and adults were faster to identify contextual/functional relations for manipulable than for nonmanipulable objects. Conversely, they were faster to identify perceptual similarity relations for nonmanipulable than for manipulable objects, particularly for natural concepts. Results reveal an early distinction between concepts of manipulable and nonmanipulable objects. Implications for further research on concept formation and for embodied views of concepts are discussed.     

从知觉分心任务看儿童类比推理能力的发展

采用四类图片类比映射任务,考察了知觉分心对90名4岁、5岁、6岁儿童类比推理能力发展的影响,并进一步阐释影响儿童类比推理能力发展的可能机制。四类图片类比映射任务分别为一种关系无分心任务、一种关系有分心任务、两种关系无分心任务和两种关系有分心任务。结果表明：（1）在具备相应知识经验的前提下,知觉分心对儿童类比推理成绩有显著影响,儿童在无分心任务中的表现明显好于知觉分心任务的表现。在无分心条件下,4岁儿童已经开始能够选择关系匹配来正确完成类比推理。错误分析发现知觉分心任务中儿童所犯错误主要是分心错误,而且分心错误随年龄增长呈下降趋势。这表明对知觉分心的抑制控制可能是儿童类比推理能力发展的一个重要影响因素。（2）随着年龄增长,儿童类比推理能力逐渐提高。总体表现为6岁组的成绩显著优于4岁、5岁组的成绩,而4岁组的成绩与5岁组的成绩没有显著差异。5岁可能是儿童能够抑制知觉分心进行类比推理的快速发展期     

Visual-touch perceptual equivalence for shape information in children and adults

Although there has been substantial developmental research which has compared shape information processing performance under visual and touch conditions, there has been little work that bears on the shape attributes that are routinely employed, or on the similarity between shape attributes employed by adults and those employed by children. The present research was carried out to investigate the visual-touch perceptual equivalence of young children, using multidimensional scaling techniques, and to compare the visual and touch perceptual structures of this age group with those of adults. The results provide evidence for adult-like perceptions of shape among 6-year-olds, in terms of both the patterns of interstimulus similarities and the shape attributes attended to by children using each modality. In addition, it was found that children have somewhat more visual-touch perceptual equivalence than adults do.     

Perceptual development and categorization: I. An investigation of task demands, stimulus set similarity, and age

This research addressed the apparent inconsistency in the literature between perceptual development as a progression of increasing separability (Shepp, 1978; Smith & Kemler, 1977, 1978) and categorization as a process based on overall similarity relations across development (Mervis, 1980; Mervis & Rosch, 1981). The influence of task demands, stimulus set similarity, and age on organizing principles of perceptual similarity were examined. Findings suggest that stimulus set similarity is an important factor in determining organizing principles of similarity for both nursery school children and adults.