Study preferences for exemplar variability in self-regulated category learning

Increasing exemplar variability during category learning can enhance classification of novel exemplars from studied categories. Four experiments examined whether participants preferred variability when making study choices with the goal of later classifying novel exemplars. In Experiments 1–3, participants were familiarised with exemplars of birds from multiple categories prior to making category-level assessments of learning and subsequent choices about whether to receive more variability or repetitions of exemplars during study. After study, participants classified novel exemplars from studied categories. The majority of participants showed a consistent preference for variability in their study, but choices were not related to category-level assessments of learning. Experiment 4 provided evidence that study preferences were based primarily on theoretical beliefs in that most participants indicated a preference for variability on questionnaires that did not include prior experience with exemplars. Potential directions for theoretical development and applications to education are discussed.     

Measuring category intuitiveness in unconstrained categorization tasks

What makes a category seem natural or intuitive? In this paper, an unsupervised categorization task was employed to examine observer agreement concerning the categorization of nine different stimulus sets. The stimulus sets were designed to capture different intuitions about classification structure. The main empirical index of category intuitiveness was the frequency of the preferred classification, for different stimulus sets. With 169 participants, and a within participants design, with some stimulus sets the most frequent classification was produced over 50 times and with others not more than two or three times. The main empirical finding was that cluster tightness was more important in determining category intuitiveness, than cluster separation. The results were considered in relation to the following models of unsupervised categorization: DIVA, the rational model, the simplicity model, SUSTAIN, an Unsupervised version of the Generalized Context Model (UGCM), and a simple geometric model based on similarity. DIVA, the geometric approach, SUSTAIN, and the UGCM provided good, though not perfect, fits. Overall, the present work highlights several theoretical and practical issues regarding unsupervised categorization and reveals weaknesses in some of the corresponding formal models.     

Tracking Multiple Statistics: Simultaneous Learning of Object Names and Categories in English and Mandarin Speakers

Two experiments were conducted to examine adult learners' ability to extract multiple statistics in simultaneously presented visual and auditory input. Experiment 1 used a cross‐situational learning paradigm to test whether English speakers were able to use co‐occurrences to learn word‐to‐object mappings and concurrently form object categories based on the commonalities across training stimuli. Experiment 2 replicated the first experiment and further examined whether speakers of Mandarin, a language in which final syllables of object names are more predictive of category membership than English, were able to learn words and form object categories when trained with the same type of structures. The results indicate that both groups of learners successfully extracted multiple levels of co‐occurrence and used them to learn words and object categories simultaneously. However, marked individual differences in performance were also found, suggesting possible interference and competition in processing the two concurrent streams of regularities.     

汉语语音范畴性知觉在儿童早期阅读中的作用

本研究以172名幼儿园中、大班和小学一年级的5~7岁儿童为研究对象, 测查了语音范畴性知觉、语音意识、短时记忆和汉字识别, 并通过群体差异比较、分层回归和结构方程建模的方法, 探讨了语音范畴性知觉、语音意识和早期阅读的关系。结果发现:(1)5~7岁儿童的语音范畴性知觉、语音意识能力随年龄的增加而显著提高;(2)语音范畴性知觉能力与语音意识, 特别是韵母意识和音节意识显著相关;(3)在语音与早期汉字识别能力的发展模型中, 语音范畴性知觉不直接影响汉字识别, 其对早期阅读的影响是通过语音意识的中介来实现的。     

性别刻板印象表征的形式及神经基础

本实验采用ERP技术,考察性别刻板印象的表征。结果发现,无论启动是上位范畴、子范畴、典型样例还是反例,被试对于刻板印象不一致的表征比一致的表征均诱发了波幅更大的N400,反应时更长。并且,被试对于性别刻板印象的表征存在层级差异。研究结果表明：（1）性别刻板印象的表征存在层级结构。（2）语义启动下,性别刻板印象违背诱发N400效应。（3）性别刻板印象表征存在自上而下的由大脑额叶进行的语义分类加工。     

Categorization by groups and individuals

Categorization is a core psychological process that is central to decision making. While a substantial amount of research has been conducted to examine individual categorization behavior, little is known about how the outputs of individual and group categorization may differ. Four experiments demonstrate that group categorization differs systematically from individual categorization in the structural dimension of category breadth: categorizing the same set of items, groups tend to create a larger number of smaller categories than individuals. This effect of social context is a function of both taskwork and teamwork. In terms of taskwork, groups’ greater available knowledge mediates differences in category breadth between individuals and groups by increasing utilized knowledge (study 2). In terms of teamwork, task conflict moderates the effect of social context on category breadth (study 3). Moreover, the experience of categorizing individually or in a group influences individuals’ subsequent judgments (study 4).     

Exemplars, prototypes, similarities, and rules in category representation: an example of hierarchical bayesian analysis

This article demonstrates the potential of using hierarchical Bayesian methods to relate models and data in the cognitive sciences. This is done using a worked example that considers an existing model of category representation, the Varying Abstraction Model (VAM), which attempts to infer the representations people use from their behavior in category learning tasks. The VAM allows for a wide variety of category representations to be inferred, but this article shows how a hierarchical Bayesian analysis can provide a unifying explanation of the representational possibilities using 2 parameters. One parameter controls the emphasis on abstraction in category representations, and the other controls the emphasis on similarity. Using 30 previously published data sets, this work shows how inferences about these parameters, and about the category representations they generate, can be used to evaluate data in terms of the ongoing exemplar versus prototype and similarity versus rules debates in the literature. Using this concrete example, this article emphasizes the advantages of hierarchical Bayesian models in converting model selection problems to parameter estimation problems, and providing one way of specifying theoretically based priors for competing models.     

Exposure to Parental Cigarette Smoking and Child Problem Behaviors: A Longitudinal Study

This study examined exposure to environmental tobacco smoke (ETS), a major public health problem. ETS has been found to be associated with an increased risk of adverse health effects in children. This study utilizes data from a community-based, longitudinal investigation examining the relation between children’s exposure to ETS and later internalizing symptoms and externalizing behaviors. Interviews were administered to a representative community sample of participants from two New York State counties in 1983, with subsequent interviews in 1985–1986, 1992, 1997, and 2002–2003 (when the participants’ mean age was 32). Data was collected on various personality and behavioral characteristics of the participants, and on internalizing symptoms and externalizing behaviors demonstrated by their children. Results indicated that children’s exposure to ETS was associated with an increased risk for both internalizing symptoms and externalizing behaviors. This relationship was maintained despite control on a number of parental psychosocial risk factors (e.g., demographic variables, personality and behavioral attributes) that have been found to be associated with both parental cigarette smoking and behavior problems among children. These data, which indicate an association between exposure to ETS and internalizing symptoms and externalizing behaviors among children, support public health policies to further restrict children’s exposure to ETS.     

Differential effects of regulatory fit on category learning

Motivation affects the degree to which people engage in tasks as well as the processes that they bring to bear. We explore the proposal that a fit between a person’s situationally induced self-regulatory focus and the reward structure of the task that they are pursuing supports greater flexibility in processing than does a mismatch between regulatory focus and reward structure. In two experiments, we prime regulatory focus and manipulate task reward structure. Our participants perform a rule-based learning task whose solution requires flexible strategy testing as well as an information-integration task for which flexible strategy use hinders learning. Across two experiments, we predict and obtain a three-way interaction between regulatory focus, reward structure, and task. Relative to a mismatch, a match leads to better rule-based task performance, but worse performance on the information-integration task. We relate these findings to other work on motivation and choking under pressure.     

Creating cluster‐specific purchase profiles from point‐of‐sale scanner data and geodemographic clusters: improving category management at a major US grocery chain

In the retail grocery industry, category management is the process of managing categories of products for greater profitability and customer value. Category management is a data‐driven process and, as a result, can benefit from point‐of‐sale (POS) scanner data. This paper describes the results of a one‐year project that shows how to use POS scanner data and geodemographic clusters to improve the practice of category management at Price Chopper, a large US grocery chain. The paper demonstrates how to merge POS scanner data with geodemographic clusters to create detailed purchase profiles that provide valuable information to category managers. It also discusses the trials and tribulations of using scanner data and provides several findings as implications (eg store‐specific promotions should be more effective than chain‐wide promotions for stores servicing a small number of geodemographic clusters with distinct shopping profiles) that supermarket managers can immediately use to improve existing promotional strategies. The paper's contents should be relevant to academicians and practitioners interested in improving the practice of category management in the UK, USA, Western Europe and Australia. Copyright © 2004 Henry Stewart Publications.