Unsupervised categorization with a child sample: category cohesion development

Studies into categorization have demonstrated that the ability to form concepts is an essential ability in cognitive development. For example, before a decision about anything can be made, firstly category concepts need to be acquired in order to make efficient decisions about that situation. The present study explored a particular type of category learning, not previously explored in this particular context – unsupervised categorization with 16 items and two dimensions, and comparing specifically children vs. adults. Previous studies have typically focused on simpler designs such as three items of two dimensions in the triad tasks, or a greater number of dimensions but with much fewer items per category in other unsupervised settings. This study investigated unsupervised categorization with two levels of task difficulty, and compared two different populations, children and adults. The findings revealed that adults performed better for the easy condition but there was no difference between these groups for the more difficult category task. The findings also revealed that unsupervised categorization in more complex settings result in more one dimensional sorting, for both children and adults. The results are discussed in the context of unsupervised categorization development abilities in children.     

Learning and transfer of category knowledge in an indirect categorization task

Knowledge representations acquired during category learning experiments are ‘tuned’ to the task goal. A useful paradigm to study category representations is indirect category learning. In the present article, we propose a new indirect categorization task called the “same”–“different” categorization task. The same–different categorization task is a regular same–different task, but the question asked to the participants is about the stimulus category membership instead of stimulus identity. Experiment 1 explores the possibility of indirectly learning rule-based and information-integration category structures using the new paradigm. The results suggest that there is little learning about the category structures resulting from an indirect categorization task unless the categories can be separated by a one-dimensional rule. Experiment 2 explores whether a category representation learned indirectly can be used in a direct classification task (and vice versa). The results suggest that previous categorical knowledge acquired during a direct classification task can be expressed in the same–different categorization task only when the categories can be separated by a rule that is easily verbalized. Implications of these results for categorization research are discussed.     

Developmental and social determinants of religious social categorization

The purpose of this study was to assess developmental and social determinants of the age at which children become aware that the social environment can be marked by categorization into religious groups and that those groups are associated with different religious beliefs. The results show that middle childhood is a critical period for this religious social categorization. Moreover, social factors play a role in the development. Religious categorization is likely to appear sooner in children attending heterogeneous schools than in those at homogeneous schools, and children from the minority religious group in the country understand religious categorization earlier than children from the majority group. However, no relation was found between the age at which religious categorization was understood and parents' religious socialization practices. This study is of both theoretical and practical interest: It complements what is already known about gender, race, and ethnic categorization by integrating developmental and social frameworks, and it can serve as a guideline for educational programs.     

Developmental and Social Determinants of Religious Social Categorization

The purpose of this study was to assess developmental and social determinants of the age at which children become aware that the social environment can be marked by categorization into religious groups and that those groups are associated with different religious beliefs. The results show that middle childhood is a critical period for this religious social categorization. Moreover, social factors play a role in the development. Religious categorization is likely to appear sooner in children attending heterogeneous schools than in those at homogeneous schools, and children from the minority religious group in the country understand religious categorization earlier than children from the majority group. However, no relation was found between the age at which religious categorization was understood and parents’ religious socialization practices. This study is of both theoretical and practical interest: It complements what is already known about gender, race, and ethnic categorization by integrating developmental and social frameworks, and it can serve as a guideline for educational programs.     

The ecological validity of the “who said what?” technique: An examination of the role of self‐involvement,cognitive interference and acquaintanceship

Questions are raised about the possible ecological invalidity of the traditional “who said what?” (WSW) procedure. Three studies are reported which use a modified, quasi‐naturalistic version of the WSW technique, in which rather than being passive recipients of presented information, participants instead play an active role in the production of such information in an interactive context. Data are presented that demonstrate that the social categorization effect typically obtained through the traditional WSW procedure generalizes beyond the circumstances in which it was initially demonstrated. Thus, in Study 1 it was established that social categories (gender, in this case) are cognitively used in real interactions between participants in order to organize information. Moreover, Study 2 demonstrated that the use of categories is accentuated when, as is typical in real world situations, recollections are not made immediately after the perception of the relevant stimuli but following a period of intervening cognitive activity. The findings of Study 3, however, suggest that the WSW technique may not inevitably lead to social categorization effects: typical effects did not appear when participants knew each other well, and therefore saw one another as unique, idiosyncratic individuals, rather than as category members.     

Information-accumulation theory of speeded categorization

A process model of perceptual categorization is presented, in which it is assumed that the earliest stages of categorization involve gradual accumulation of information about object features. The model provides a joint account of categorization choice proportions and response times by assuming that the probability that the information-accumulation process stops at a given time after stimulus presentation is a function of the stimulus information that has been acquired. The model provides an accurate account of categorization response times for integral-dimension stimuli and for separable-dimension stimuli, and it also explains effects of response deadlines and exemplar frequency.     

A probabilistic threshold model: Analyzing semantic categorization data with the Rasch model

According to the Threshold Theory (Hampton, 1995, 2007) semantic categorization decisions come about through the placement of a threshold criterion along a dimension that represents items' similarity to the category representation. The adequacy of this theory is assessed by applying a formalization of the theory, known as the Rasch model (Rasch, 1960; Thissen & Steinberg, 1986), to categorization data for eight natural language categories and subjecting it to a formal test. In validating the model special care is given to its ability to account for inter- and intra-individual differences in categorization and their relationship with item typicality. Extensions of the Rasch model that can be used to uncover the nature of category representations and the sources of categorization differences are discussed.     

社会分类的概念、线索及影响机制

作为社会认知的基本过程和重要途径,社会分类对预测刻板印象和群际感知、减少多元文化群体中的关系冲突、促进推理与决策以及指导社会关系推断等都有重要作用。人们进行社会分类的线索可以概括为明显线索和模糊线索、自然线索和社会线索以及静态线索和动态线索。社会分类会受到分类对象、情境和感知者等的作用,同时对人们认知、情绪、情感和行为等产生一系列影响。未来可以基于跨文化和发展视角探讨社会分类的线索偏向、潜在机制及立足本土文化检验社会分类的影响及干预策略。     

Sequence effects in categorization of simple perceptual stimuli

Categorization research typically assumes that the cognitive system has access to a (more or less noisy) representation of the absolute magnitudes of the properties of stimuli and that this information is used in reaching a categorization decision. However, research on identification of simple perceptual stimuli suggests that people have very poor representations of absolute magnitude information and that judgments about absolute magnitude are strongly influenced by preceding material. The experiments presented here investigate such sequence effects in categorization tasks. Strong sequence effects were found. Classification of a borderline stimulus was more accurate when preceded by a distant member of the opposite category than by a distant member of the same category. It is argued that this category contrast effect cannot be accounted for by extant exemplar or decision-bound models of categorization. The effect suggests the use of relative magnitude information in categorization. A memory and contrast model illustrates how relative magnitude information may be used in categorization.     

Generalization: A Practice of Situated Categorization in Talk

This paper analyzes four instances in talk of generalization about people, that is, of using statements about one or more people as the basis of stating something about a category. Generalization can be seen as a categorization practice which involves a reflexive relationship between the generalized-from person or people and the generalized-to category. One thing that is accomplished through generalization is instruction in how to understand the identity of the generalized-from person or people, so in addition to being understood as a practice of categorization, generalization can also be understood as a practice of identification. Somewhat incidentally, this paper also illustrates the importance of certain methodological issues related to membership categorization analysis and contributes to the growing body of work that connects membership categorization analysis with sequential conversation analysis.     

Naming pictures at no cost: asymmetries in picture and word conditional naming

We report a striking finding about naming and categorization of pictures and reading aloud and categorization of words. The categorization of a word before reading it aloud leads to an increase in response time as compared with the condition in which naming is not conditional on the categorization of the word. Quite differently, no cost is associated with the conditional naming of pictures. Results are discussed in terms of multiple procedures operating on pictorial and verbal stimuli to retrieve phonological forms.     

交叉分类及其对刻板印象的影响

社会分类(分类)是群体认知和印象评价的依据, 交叉分类作为一种认知过程, 是指在知觉或评价他人时, 同时在两个或多个类别维度上进行社会分类, 形成在多个类别维度上内外群体身份的交叉。研究发现交叉分类既可以降低刻板印象, 也可以增强刻板印象。对此, 类别化视角的解释强调群体身份的作用, 而个体化视角的解释强调多重类别背景下去类别化的作用。现有的研究在如何理解并考察这一影响的不同方向上仍存在分歧, 同时, 也未能认识到刻板印象对于个体认知与认同的意义, 存在明显不足。今后的研究应重点探讨类别化视角的动机与认知过程, 个体化视角的优势类别与加工方式, 以及以自我归类为基础的整合。     

Categorization in everyday life: the effects of positive and negative categorizations on emotions and self‐views

This study investigates how everyday categorization experiences affect people's emotional responses and self‐views. A representative Dutch population sample (N = 463) was asked to recount a situation in which they were categorized by others. This resulted in a range of categories that were spontaneously evoked by research participants. Participants were asked to think of a situation either where the categorization resulted in negative or in positive expectations about the self. Positive categorization elicited more positive emotions and agreement than negative categorization. However, when positive expectations about the self were formed, people found it less easy to detect that these were based on external categorizations, and were less likely to protest. Mediational analyses showed that because detection was impaired, exposure to positive categorization resulted in lower self‐confidence than exposure to negative categorization. Copyright © 2006 John Wiley & Sons, Ltd.     

Technique for estimating perceptual noise in categorization tasks

A procedure, based on the method of adjustment, for estimating perceptual noise is presented. The resulting estimates can be used to obtain a better understanding of categorization behavior, to answer questions about the distributional form of perceptual noise, and to test for perceptual independence. All three applications are demonstrated in a categorization task involving two categories.     

The distributional structure of grammatical categories in speech to young children

We present a series of three analyses of young children's linguistic input to determine the distributional information it could plausibly offer to the process of grammatical category learning. Each analysis was conducted on four separate corpora from the CHILDES database (MacWhinney, 2000) of speech directed to children under 2;5. We showthat, in accord with other findings, a distributional analysis which categorizeswords based on their co‐occurrence patterns with surroundingwords successfully categorizes the majority of nouns and verbs. In Analyses 2 and 3, we attempt to make our analyses more closely relevant to natural language acquisition by adopting more realistic assumptions about howyoung children represent their input. In Analysis 2, we limit the distributional context by imposing phrase structure boundaries, and find that categorization improves even beyond that obtained from less limited contexts. In Analysis 3, we reduce the representation of input elements which young children might not fully process and we find that categorization is not adversely affected: Although noun categorization is worse than in Analyses 1 and 2, it is still good; and verb categorization actually improves. Overall, successful categorization of nouns and verbs is maintained across all analyses. These results provide promising support for theories of grammatical category formation involving distributional analysis, as long as these analyses are combined with appropriate assumptions about the child learner's computational biases and capabilities.     

A rule-based categorization deficit in Alzheimer's disease?

This study examined the categorization processes that Alzheimer's disease (AD) patients use during assessments of semantic memory. Rule-based categorization involves the careful, analytic processing of strict criteria to determine category membership, particularly for items from graded categories with ambiguous category membership; similarity-based categorization requires an overall comparison of a test stimulus with a prototype or remembered exemplar of the category and is relatively effective for the rapid categorization of items with unambiguous category membership. To assess these processes in AD, patients were asked to decide the category membership of test stimuli for categories with poorly defined or fuzzy boundaries (e.g., VEGETABLE) and for categories with well-defined boundaries (e.g., FEMALE) and then to judge the representativeness of the test stimulus for its chosen category. A subgroup of AD patients demonstrated a typical pattern of impaired semantic memory compared to healthy control subjects; that is, difficulty deciding the category membership of test items from fuzzy categories. Among these patients, we found no deficit in category membership decisions about items taken from well-defined categories. We also found that AD patients and healthy controls do not differ in their representativeness judgments of items within a correctly judged category. These findings are most consistent with the hypothesis that rule-based categorization difficulty limits semantic memory in AD.     

Are there representational shifts during category learning?

Early theories of categorization assumed that either rules, or prototypes, or exemplars were exclusively used to mentally represent categories of objects. More recently, hybrid theories of categorization have been proposed that variously combine these different forms of category representation. Our research addressed the question of whether there are representational shifts during category learning. We report a series of experiments that tracked how individual subjects generalized their acquired category knowledge to classifying new critical transfer items as a function of learning. Individual differences were observed in the generalization patterns exhibited by subjects, and those generalizations changed systematically with experience. Early in learning, subjects generalized on the basis of single diagnostic dimensions, consistent with the use of simple categorization rules. Later in learning, subjects generalized in a manner consistent with the use of similarity-based exemplar retrieval, attending to multiple stimulus dimensions. Theoretical modeling was used to formally corroborate these empirical observations by comparing fits of rule, prototype, and exemplar models to the observed categorization data. Although we provide strong evidence for shifts in the kind of information used to classify objects as a function of categorization experience, interpreting these results in terms of shifts in representational systems underlying perceptual categorization is a far thornier issue. We provide a discussion of the challenges of making claims about category representation, making reference to a wide body of literature suggesting different kinds of representational systems in perceptual categorization and related domains of human cognition.     

Situational information contributes to object categorization and inference

Three experiments demonstrated that situational information contributes to the categorization of functional object categories, as well as to inferences about these categories. When an object was presented in the context of setting and event information, categorization was more accurate than when the object was presented in isolation. Inferences about the object similarly became more accurate as the amount of situational information present during categorization increased. The benefits of situational information were higher when both setting and event information were available than when only setting information was available. These findings indicate that situational information about settings and events is stored with functional object categories in memory. Categorization and inference become increasingly accurate as the information available during categorization matches situational information stored with the category.     

The role of explanation in categorization decisions

Research into the role of explanation on the categorization process has yielded conflicting conclusions. Some theorists stress the importance of explanation, arguing that explanations provide a causal structure necessary to the categorization process. Others discount its significance, arguing that explanation is neither necessary nor sufficient for categorization. Experimentally, explanation has shown modest success in accounting for some categories but not others. Across three experiments, we test whether the central features of a category are the ones that capture the most explanatory structure. The objectives of the current study are threefold: to determine the importance of explanation in natural kind and artifact categorization; to understand the implications of feature correlations as they relate to explanation; and to further delineate the benefit of explanation outside of a functional role. Experiment 1 demonstrates that explanation plays a more dominant role in artifact versus natural kind categorization. Experiment 2 provides evidence that correlated features are neither necessary nor sufficient for categorization. Moreover, it demonstrates that, in the absence of correlation, people still rely on explanation for artifacts but not for natural kinds. Experiment 3 tests to what extent functional information underlies explanation in artifact categorization. We demonstrate that functional relations are not necessary for explanatory‐based categorization. Our results, coupled with previous evidence, suggest a dichotomous role for explanation‐based categorization. On the one hand, explanation is virtually ignored when categorizing biological kinds; on the other, explanation fosters artifact categorization. Implications for categorization and category‐specific disorder are considered.