Choice Of Categories Research Articles

Blending incremental and stratified layering techniques to produce an esthetic posterior composite resin restoration with a predictable prognosis.

Composite resin restorations play an ever-increasing role as routine restorations in everyday clinical practice. However, the long-term prognosis of these restorations is still widely debated and open to question. The restorative protocols are still evolving, whether for direct or indirect placement, and little evidence is available in the scientific literature as to the ideal choice of site, technique, and category for placement. This article discusses the problems encountered and suggests a clinical restorative protocol to optimize composite resin placement.

The contribution of speech rate and pitch variation to the perception of vocal emotions in a German and an American sample

The present study examined acoustic cue utilisation for perception of vocal emotions. Two sets of vocal-emotional stimuli were presented to 35 German and 30 American listeners: (1) sentences in German spoken with five different vocal emotions; and (2) systematically rate- or pitch-altered versions of the original emotional stimuli. In addition to response frequencies on emotional categories, activity ratings were obtained. For the systematically altered stimuli, slow rate was reliably associated with the “sad” label. In contrast, fast rate was classified as angry, frightened, or neutral. Manipulation of pitch variation was less potent than rate manipulation in influencing vocal emotional category choices. Reduced pitch variation was associated with perception as sad or neutral; greater pitch variation increased frightened, angry, and happy responses. Performance was highly similar for the two samples, although across tasks, German subjects perceived greater variability of activity in the emotional stimuli than did American participants.

The contribution of speech rate and pitch variation to the perception of vocal emotions in a German and an American sample

The present study examined acoustic cue utilisation for perception of vocal emotions. Two sets of vocal-emotional stimuli were presented to 35 German and 30 American listeners: (1) sentences in German spoken with five different vocal emotions; and (2) systematically rate- or pitch-altered versions of the original emotional stimuli. In addition to response frequencies on emotional categories, activity ratings were obtained. For the systematically altered stimuli, slow rate was reliably associated with the “sad” label. In contrast, fast rate was classified as angry, frightened, or neutral. Manipulation of pitch variation was less potent than rate manipulation in influencing vocal emotional category choices. Reduced pitch variation was associated with perception as sad or neutral; greater pitch variation increased frightened, angry, and happy responses. Performance was highly similar for the two samples, although across tasks, German subjects perceived greater variability of activity in the emotional stimuli...

Queer theory and the creation of contextual subject access tools for gay and lesbian communities

Knowledge organization research has come to question the theoretical distinction between aboutness (a document's innate content) and meaning (the use to which a document is put). This distinction has relevance beyond Information Studies, particularly in relation to homosexual concerns. Literary criticism, in particular, frequently addresses the question: when is a work about homosexuality? This paper explores this literary debate and its implications for the design of subject access systems for gay and lesbian communities. By examining the literary criticism of Herman Melville's Billy Budd, particularly in relation to the theories of Eve Kosofsky Sedgwick in The Epistemology of the Closet (1990), this paper exposes three tensions that designers of gay and lesbian classifications and vocabularies can expect to face. First is a tension between essentialist and constructivist views of homosexuality, which will affect the choice of terms, categories, and references. Second is a tension between minoritizing and universalizing perspectives on homosexuality. Third is a redefined distinction between aboutness and meaning, in which aboutness refers not to stable document content, but to the system designer's inescapable social and ideological perspectives. Designers of subject access systems can therefore expect to work in a context of intense scrutiny and persistent controversy

Testing a Framework for Reliable Classification of Usability Problems

The User Action Framework (UAF) is a knowledge base of usability issues and concepts structured to provide a framework and method for classifying usability problems identified during usability evaluation. The UAF is essentially a hierarchical structure of usability attributes that users traverse as a decision structure, selecting the most appropriate classification category and sub-category at each level of the hierarchy. The cumulative set of category choices along the classification path is taken as a sequence of usability attributes that determines a complete classification description of the usability problem in question. The UAF itself has been the subject of usability evaluation and is the product of an extensive, iterative design process. In this paper we report on the reliability of the UAF by measuring the agreement of 10 experienced usability practitioners as they classify 15 different usability problems.

Consumer intentions to use a service category

Even though service marketers are interested in influencing customer choice at the service provider level (i.e. the service brand level), the decision to patronize a particular service firm seldom occurs until after the customer decides to use a service provider in the first place. Ultimately, this initial “make‐or‐buy” purchase decision – the decision to use a service category – restrains customer decisions at the service provider (brand) level. To enhance our understanding of customers’ service category decisions, a double cross‐validation approach was employed to investigate the applicability of a service category choice model which we adapted from Howard’s work on consumer decision making. Our model, which was tested with two different service categories, was supported.

Long-Term Trends in Profitability: The Recovery of World War II

It has become accepted doctrine among economists that the rate of profit in the United States has declined since the mid-1960s. What is less a matter of agreement is whether this decline represents a stage in a long-term secular decline. In a recent article Dumenil, Glick, and Rangel (1987) reviewed the existing empirical evidence on this topic and found that independent of variation in the definition of the rate of profit. Any series extending back to 1929 reveals a stable or increasing trend. Although two periods of serious decline exist (after World War I and in the late 1950s) they are connected by a during World War II In fact in any measure which does not subtract taxes from profit World War II coincides with a considerable restoration of the rate of profit. This is an important anomaly for Marxists who predict a long-term declining tendency yet it has never been addressed in the empirical literature on this topic. There is no doubt that a restoration of the rate of profit discovered in the 1940s questions the relevance of Marx's famous thesis of a falling tendency of the rate of profit in capitalist economics. Certainly when Marx discussed the tendency of the rate of profit he acknowledged the important role of countertendencies. However one would not expect the counter tendencies which Marx discussed to have such a concentrated impact over such a short span of time. The purpose of the present study is to investigate more carefully this leap forward in profitability. In a first part we will fully explore the statistical characteristics of the leap forward. Specifically we will compare the leap forward with earlier and future fluctuations and trends in profitability (an effort will be made in spite of the deficiencies of the data, to cover a period of 120 years). We will further determine whether the leap forward is invariant to the choice of the definition of the rate of profit or whether it can be explained by a specific choice of statistical categories. A second part will consider whether the leap forward is the expression of changes in the relative price of fixed capital, or a variation in the workweek of capital. The final part will explore whether the leap occurred in specific industries or whether it was a general feature of the economy. In the conclusion we will discuss a number of further alternative explanations.

Estimating phytoplankton carbon from microscopic counts: an application for riverine systems

Algal biomass, in addition to cell numbers, is a measure of the successful conversion of inorganic to organic carbon. Consequently, carbon is the main currency used in aquatic models and in flux and budget studies. On the other hand, microscopic observation and counts remain the only means for determining species composition and biomass, which is relevant to many aspects of aquatic ecology. In this study, we focus on the way to convert biovolume to carbon biomass for algal assemblages of two rivers, using a computerized system that records dimensions of phytoplankton (Gosselain & Hamilton, 2000). We first compare different equations found in the literature for converting algal cell volume to cellular carbon content. We then evaluate the accuracy of a biomass estimate based on less time-consuming measurements, using pre-determined biovolume values instead of measuring cells in all samples. Biovolume/carbon equations are evaluated using total phytoplankton carbon biomass determined from measured chlorophyll a. Equations established for freshwater taxa seem to provide better estimates of algal biomass in the two case studies presented here, the Rideau and Meuse rivers (Canada and Belgium, respectively) than do more numerous equations defined for marine taxa. Furthermore, equations that make a distinction between diatoms and other algae appear more appropriate than those considering all algal groups as a whole. Finally, mean values of algal biovolumes, determined using sufficient measurements of cell dimensions from representative sampling series, may prove sufficient for carbon estimates of taxa in relatively homogenous size ranges. The careful choice of appropriate volumetric shapes and taxa categories remains of prime importance to get precise results.

Comparison in the Development of Categories

Recent research on children's word learning has led to a paradox. Although word learning appears to be a deep source of insight into conceptual knowledge for children, preschoolers often categorize objects on the basis of shallow perceptual features such as shape. The current studies seek to resolve this discrepancy. We suggest that comparing multiple instances of a category enables children to extract deeper relational commonalities among category members. We examine 4-year-olds' categorization behaviors when asked to select a match for a target object (e.g., an apple) between a perceptually similar, out-of-kind object (e.g., a balloon) and a perceptually different category match (e.g., a banana). Children who learn a novel word as a label for multiple instances of the category are more likely to select the category match over the perceptual match. Children who learn a label for only one instance are equally likely to select either alternative. This effect is present even when individual target instances are more perceptually similar to the perceptual choice than to the category choice. We conclude that structural alignment processes may be important in the development of category understanding.

The “Shopping Basket”: A Model for Multicategory Purchase Incidence Decisions

Consumers make multicategory decisions in a variety of contexts such as choice of multiple categories during a shopping trip or mail-order purchasing. The choice of one category may affect the selection of another category due to the complementary nature (e.g., cake mix and cake frosting) of the two categories. Alternatively, two categories may co-occur in a shopping basket not because they are complementary but because of similar purchase cycles (e.g., beer and diapers) or because of a host of other unobserved factors. While complementarity gives managers some control over consumers' buying behavior (e.g., a change in the price of cake mix could change the purchase probability of cake frosting), co-occurrence or co-incidence is less controllable. Other factors that may affect multi-category choice may be (unobserved) household preferences or (observed) household demographics. We also argue that not accounting for these three factors simultaneously could lead to erroneous inferences. We then develop a conceptual framework that incorporates complementarity, co-incidence and heterogeneity (both observed and unobserved) as the factors that could lead to multi-category choice. We then translate this framework into a model of multi-category choice. Our model is based on random utility theory and allows for simultaneous, interdependent choice of many items. This model, the multi variate probit model, is implemented in a Hierarchical Bayes framework. The hierarchy consists of three levels. The first level captures the choice of items for the shopping basket during a shopping trip. The second level captures differences across households and the third level specifies the priors for the unknown parameters. We generalize some recent advances in Markov chain Monte Carlo methods in order to estimate the model. Specifically, we use a substitution sampler which incorporates techniques such as the Metropolis Hit-and-Run algorithm and the Gibbs Sampler. The model is estimated on four categories (cake mix, cake frosting, fabric detergent and fabric softener) using multicategory panel data. The results disentangle the complementarity and co-incidence effects. The complementarity results show that pricing and promotional changes in one category affect purchase incidence in related product categories. In general, the cross-price and cross-promotion effects are smaller than the own-price and own-promotions effects. The cross-effects are also asymmetric across pairs of categories, i.e., related category pairs may be characterized as having a “primary” and a “secondary” category. Thus these results provide a more complete description of the effects of promotional changes by examining them both within and across categories. The co-incidence results show the extent of the relationship between categories that arises from uncontrollable and unobserved factors. These results are useful since they provide insights into a general structure of dependence relationships across categories. The heterogeneity results show that observed demographic factors such as family size influence the intrinsic category preference of households. Larger family sizes also tend to make households more price sensitive for both the primary and secondary categories. We find that price sensitivities across categories are not highly correlated at the household level. We also find some evidence that intrinsic preferences for cake mix and cake frosting are more closely related than preferences for fabric detergent and fabric softener. We compare our model with a series of null models using both estimation and holdout samples. We show that both complementarity and co-incidence play a significant role in predicting multicategory choice. We also show how many single-category models used in conjunction may not be good predictors of joint choice. Our results are likely to be of interest to retailers and manufacturers trying to optimize pricing and promotion strategies across many categories as well as in designing micromarketing strategies. We illustrate some of these benefits by carrying out an analysis which shows that the “true” impact of complementarity and co-incidence on profitability is significant in a retail setting. Our model can also be applied to other domains. The combination of item interdependence and individual household level estimates may be of particular interest to database marketers in building customized “cross-selling” strategies in the direct mail and financial service industries.

Bisimulation and Open Maps for Timed Transition Systems

Formal models for real-time systems have been studied intensively over the past decade. Much of the theory of untimed systems have been lifted to real-time settings. One example is the notion of bisimulation applied to timed transition systems, which is studied here within the general categorical framework of open maps. We define a category of timed transition systems, and show how to characterise standard timed bisimulation in terms of spans of open maps with a natural choice of a path category. This allows us to apply general results from the theory of open maps, e.g. the existence of canonical models and characteristic logics. Also, we obtain here an alternative proof of decidability of bisimulation for finite transition systems, and illustrate the use of open maps in finite presentations of bisimulations

Face vs. empathy: the social foundation of Maithili verb agreement

Maithili features one of the most complex agreement systems of any Indo-Aryan language. Not only nominative and non-nominative subjects, but also objects, other core arguments, and even nonarguments are cross-referenced, allowing for a maximum of three participants encoded by the verb desinences. The categories reflected in the morphology are person, honorific degree, and, in the case of third persons, gender, spatial distance, and focus. However, not all combinations of category choices are equally represented, and there are many cases of neutralization. We demonstrate that the paradigm structure of Maithili verb agreement is not arbitrary but can be predicted by two general principles of interaction in Maithil society: a principle of social hierarchy underlying the evaluation of people's “face” (Brown and Levinson 1987[1978]), and a principle of social solidarity defining degrees of “empathy” (Kuno 1987) to which people identify with others. Maithili verb agreement not only reflects a specific style of social cognition but also constitutes a prime means of maintaining this style by requiring constant attention to its defining parameters. In line with this, we find that the system is partly reduced by uneducated, so-called lower-caste speakers, who are least interested in maintaining this style, especially its emphasis on hierarchy.

A fuzzy adaptive resonance theory—supervised predictive mapping neural network applied to the classification of multivariate chemical data

A fuzzy adaptive resonance theory—supervised predictive mapping (Fuzzy ARTMAP) neural network has been studied for the classification of multivariate chemical data. Fuzzy ARTMAP achieves a synthesis of fuzzy logic and adaptive resonance theory (ART) by exploiting the close formal similarity between the computations of fuzzy subset membership and ART category choice, resonance, and learning. To examine the properties of Fuzzy ARTMAP, the well-known Italian olive oil data set was employed. Then this method was applied to a practical agricultural data set to classify different soil samples depending on the crops grown on them. For comparison, the back-propagation (BP) neural network has also been used to treat these data. The results show that the classification performance of the Fuzzy ARTMAP neural network is as good or better than the BP network in the present applications. Among other features, the Fuzzy ARTMAP needs less training time and fewer algorithmic parameters to be optimized than BP does to achieve good classification.

The Price Is Right...or is it? Demographic and category effects on consumer price knowledge

For over a quarter of a century, the television game show The Price Is Right has been testing American consumers’ knowledge of prices for a wide array of products. The settings of this highly popular game show allow for a broad examination of the extent of price knowledge consumers possess across product categories. Much of our current perspective on consumer price knowledge has been limited by a restricted choice of product categories studied, and a lack of significant respondent incentives for providing accurate price responses. Using data from hundreds of contestants, highly motivated to provide accurate price estimates, this paper studies the impact of product‐ and consumer‐related factors on consumer price knowledge across 29 product categories.

When and what to buy: a nested logit model of coffee purchase

On a shopping trip to a supermarket a customer may purchase a product in a given category and, if so, buys a particular brand. Guadagni and Little (1983) model the brand choice part of this process. A multinomial logit model describes the selection of brand and size given that the customer makes a category purchase. Explanatory variables include store actions, such as price and promotion, and customer characteristics, such as brand and size loyalty. The present paper extends the formulation to include the decision to make a purchase in the category on a shopping trip. This additional step not only provides a more complete description of the buying process but also makes possible a better calculation of sales response by including the effect of marketing actions on category sales as well as brand share. The methodology employed is a generalization of the multinomial logit, the nested logit. The shopper's decision includes two components, the selection of the category and the choice of the brand-size combination. The model of brand-size choice is essentially that of Guadagni and Little (1983). The category choice introduces further variables including household inventory, category price, and the attractiveness of purchasing a product now as opposed to later. Calibration of the nested logit is done by sequential estimation. The model, applied to regular ground coffee data collected from a scanner panel, tracks sales well in a hold-out sample, both at the aggregate and individual levels. Use of the model to calculate short term market response to store promotion demonstrates the increase in sales due to category expansion as well as share gain. © 1998 John Wiley & Sons, Ltd.

Age at menopause and breast cancer: estimation of floating absolute risks

Abstract Late menopause is consistently related to breast cancer risk, but direct comparison of the modifying effects of type of menopause and of time factors across studies has been made difficult by the heterogeneity in the choice of the reference category, and in the definition of postmenopausal status. These effects were investigated in the absence of an arbitrary baseline category by computing floating absolute risks (FARs). Pooled data from two case-control studies conducted between 1983 and 1994 in major teaching and general hospitals of six Italian centres were used. Participants were 3576 postmenopausal women with incident, histologically confirmed breast cancer, and 3578 postmenopausal controls admitted to hospital for acute, non-neoplastic, non-hormonal, non-gynaecological conditions. When all types of menopause were considered together, FARs were 0.49 for

Timed Bisimulation and Open Maps

Formal models for real-time systems have been studied intensively over the past decade. Much of the theory of untimed systems has been lifted to real-time settings. One example is the notion of bisimulation applied to timed transition systems, which is studied here within the general categorical framework of open maps. We define a category of timed transition systems, and show how to characterize standard timed bisimulation in terms of spans of open maps with a natural choice of a path category. This allows us to apply general results from the theory of open maps, e.g. the existence of canonical models and characteristic logics. Also, we obtain here an alternative proof of decidability of bisimulation for finite transition systems, and illustrate the use of open maps in finite presentations of bisimulations

Quality Tier Competition: How Price Change Influences Brand Choice and Category Choice

The authors demonstrate that competition among brands in different quality tiers can be asymmetric both in brand choice (“what”) and in category choice (“whether”). They also investigate how competition among quality tiers is affected by the direction of price changes (increase or decrease). Empirical findings from four scanner panel data sets consistently show that with price reduction, high-quality brands gain more than do low-quality brands both in “what” and “whether” decisions. Furthermore, high-quality brands are less vulnerable to losses when prices are increased. The authors conclude with implications for understanding quality tier competition and developing price promotional strategies.

Quality Tier Competition: How Price Change Influences Brand Choice and Category Choice

The authors demonstrate that competition among brands in different quality tiers can be asymmetric both in brand choice (“what”) and in category choice (“whether”). They also investigate how compet...

Perspectives on multiple category choice

Multiple category choice is a decision process in which an individualselects a number of goods, all of which are nonsubstitutable with respect toconsumption. Choices can be made either simultaneously or sequentially. Thekey feature of multiple category choice is the treatment of the choices asinterrelated because each item in the final collection of goods contributesto the achievement of a common behavioral goal. We discuss current andpotential applications of psychology, economics and consumer choice theoryin developing models of multiple category choice.