Choice frequency and similarity

Abstract.— Within the framework of a Thurstonian approach to social choice frequencies, an assumption of a positive correlation between similarity and correlation predicts smaller standard deviations of utility differences for more similar choice objects. This prediction was supported in two studies of similarity and preference, one concerned with social science disciplines and the other with Swedish political parties. Implications for understanding social choice phenomena in politics and marketing are discussed.     

Category variability, exemplar similarity, and perceptual classification

Experiments were conducted in which observers learned to classify simple perceptual stimuli into low-variability and high-variability categories. Similarities between objects were measured in independent psychological-scaling tasks. The results showed that observers classified transfer stimuli into the high-variability categories with greater probability than was predicted by a baseline version of an exemplar-similarity model. Qualitative evidence for the role of category variability on perceptual classification, which could not be explained in terms of the baseline exemplar-similarity model, was obtained as well. Possible accounts of the effects of category variability are considered in the General Discussion section.     

Dimensional,similarity, and configurai classification of integral and separable stimuli

Subjects classified sets of two-dimensional stimuli into two or three groups in any way they wished. For integral stimuli, classification was based on numerical balance and the similarity structure. For separable stimuli, classification was based on the dimensional structure and the configurai properties of the stimulus set. These results replicate and extend those of Handel and Imai (1972). In addition, they suggest that no closed set of stimulus concepts is possible.     

Articulation in the context of edge classification

Many researchers believe the human visual system classifies luminance edges into those produced by reflectance edges or those produced by illumination edges, yet this classification process is not completely understood. One suggestion is that heuristics are used for edge classification. For example. specific contrast relationships at the luminance edge ('codirectional contrast invariance' and 'transversal luminance-ratio preserving') may distinguish an illumination edge from a reflectance edge on the one hand, and from a translucent edge on the other. Distinct from luminance junctions, these features are global characteristics of the luminance pattern that make distinguishing between different types of edge easier with more highly articulated scenes. I demonstrate that apparent translucency, nonreversing X-junctions, and single-reversing X-junctions are insufficient on their own to produce the lightness illusion of Adelson's well-known tile pattern. While tolerating violations of the codirectional contrast invariance and transversal-luminance-ratio presersving without reversing the sign of contrast, the visual system is quite sensitive to such contrast reversal at the luminance edge. I account for this by suggesting that humans process lightness in terms of an ordinal, rather than interval, (or ratio) scale.     

Free classification: Element-level and subgroup-level similarity

Subjects classified sets of multidimensional stimuli into two groups in any way they wished. The sets were composed of 6 or 12 stimuli: 2 or 4 instances of 3 different stimuli (e.g., 2 blue circles, 2 green circles, 2 red circles). There were striking individual differences in the preferred classification. Some subjects maximized the similarity between subgroups by matching the composition of the subgroups--one instance of each stimulus was placed in each group. The other subjects maximized the similarity among stimuli within each subgroup by placing similar stimuli in each group (the blues and greens in one group, the reds in the other). The nature of the stimuli as well as the relationships among the three stimuli had little effect on classification. In this case, cognitive styles specific to individuals but general across diverse dimensions and stimulus sets determined classification.     

A classificatory theory of similarity

Summary This paper outlines a classificatory theory of cognitive similarity and compares it to feature approaches. The theory assumes that similarity is a function of the number of classes contained in the universe referred to in the judgments and the number of elements contained in the class defined by the two comparison stimuli. The theory is tested in a number of studies in which verbal stimuli are used. Most of the experiments concern context effects predicted by the theory. An empirical comparison is made between the classificatory theory and a feature theory. It is argued that the classificatory theory accounts for some of the data more easily than a feature approach does. Some implications for the use of similarity data in multidimensional scaling are also discussed.     

Multidimensional shape similarity in the development of visual object classification

The current work examined age differences in the classification of novel object images that vary in continuous dimensions of structural shape. The structural dimensions employed are two that share a privileged status in the visual analysis and representation of objects: the shape of discrete prominent parts and the attachment positions of those parts. Experiment 1 involved a triad classification task in which participants at each of three different ages (5 years, 8 years, and adult) classified object images from two distinct stimulus sets. Across both sets, the youngest children demonstrated a systematic bias toward the shape of discrete parts during their judgments. With increasing age, participants increasingly came to select both the shape and the position of parts when classifying the images. The findings from Experiment 2 indicate that the local shape bias observed in young children's classifications is not merely a consequence of a discrimination advantage for that dimension. Results are discussed in relation to corresponding age-related changes in other functional contexts of visual processing.     

Processes of overall similarity sorting in free classification

The processes of overall similarity sorting were investigated in 5 free classification experiments. Experiments 1 and 2 demonstrated that increasing time pressure can reduce the likelihood of overall similarity categorization. Experiment 3 showed that a concurrent load also reduced overall similarity sorting. These findings suggest that overall similarity sorting can be a time-consuming analytic process. Such results appear contrary to the idea that overall similarity is a nonanalytic process (e.g., T. B. Ward, 1983) but are in line with F. N. Milton and A. J. Wills's (2004) dimensional summation hypothesis and with the stochastic sampling assumptions of the extended generalized context model (K. Lamberts, 2000). Experiments 4 and 5 demonstrated that the relationship between stimulus presentation time and overall similarity sorting is nonmonotonic, and the shape of the function is consistent with the idea that the three aforementioned processes operate over different parts of the time course.     

Locke's theory of classification

In §155 of his New Theory of Vision Berkeley explains that a hypothetical ‘unbodied spirit’ ‘cannot comprehend the manner wherein geometers describe a right line or circle’.1 ¹All references to Berkeley are from, A. A. Luce and T. E. Jessop (eds.), The Works of George Berkeley, Bishop of Cloyne (London: Thomas Nelson and Sons, Ltd., 1948) The following abbreviations are used: An Essay Towards A New Theory of Vision, section x = New Theory x; Philosophical Commentaries, entry x = Commentaries x; Part I of A Treatise concerning the Principles of Knowledge, section x = Principles x. All other references to Berkeley's works are of the form The Works of George Berkeley, Bishop of Cloyne, volume x, page y = Works, x, y. The reason for this, Berkeley continues, is that ‘the rule and compass with their use being things of which it is impossible he should have any notion.’ This reference to geometrical tools has led virtually all commentators to conclude that at least one reason why the unbodied spirit cannot have knowledge of plane geometry is because it cannot manipulate a ruler or a compass. In this article I will show that such an interpretation is flawed. I will instead argue that Berkeley's understanding of Euclidian geometry was based on Isaac Barrow's account of the foundations of geometry. On this view geometrical objects are conceived in terms of the idealized motion that generates the objects of geometry. Consequently, that what the unbodied spirit cannot do in this context is to form an idea of motion rather than being unable to handle geometrical tools.     

A classification scheme for discipline: type, mode of administration, context

This paper reviews research related to parental disciplinary practices and presents a classification scheme discipline that separates discipline into the type and the mode of administration used. Previous research has not kept important constructs related to discipline distinct and has ignored some types of discipline, as well as the mode of administration. The classification scheme presented is meant to try to foster conceptual clarity, to advocate for attention to important aspects of disciplinary practices in future research, and to lay the groundwork for development of additional measurement tools — particularly for survey design research.     

Vertical similarity in spoken word recognition: Multiple lexical activation,individual differences,and the role of sentence context

Four experiments investigated acoustic-phonetic similarity in the mapping process between the speech signal and lexical representations (vertical similarity). Auditory stimuli were used where ambiguous initial phonemes rendered a phoneme sequence lexically ambiguous (perceptual-lexical ambiguities). A cross-modal priming paradigm (Experiments 1, 2, and 3) showed facilitation for targets related to both interpretations of the ambiguities, indicating multiple activation. Experiment 4 investigated individual differences and the role of sentence context in vertical similarity mapping. The results support a model where spoken word recognition proceeds via goodness-of-fit mapping between speech and lexical representations that is not influenced by sentence context.     

A choice theory analysis of similarity judgments

The selection of one of several stimuli as most similar to a reference stimulus is assumed to satisfy a choice axiom that permits assigning ratio scale values to each variable-reference stimuli pair. The logarithm of this scale is treated as a distance measure, leading to the following testable conclusions about the pairwise choice probabilities as the reference stimulus is varied. First, the plot is a symmetrically truncated ogive with horizontal tails. Second, if two pairs of choice stimuli have the same midpoint, the ogive of one pair is part of the ogive of the other. In terms of this model, the hysteresis and midpoint displacement effects in the method of bisection are discussed, and relations with Coombs' unfolding techniques are explored.This work was supported in part by grant G-8864 from the National Science Foundation to the University of Pennsylvania. I wish to express my appreciation to Professors Robert R. Bush and Eugene Galanter, with whom I have had a number of very helpful discussions of these ideas.     

Tests of the DRYAD theory of the age-related deficit in memory for context: not about context, and not about aging

Older adults exhibit a disproportionate deficit in their ability to recover contextual elements or source information about prior encounters with stimuli. A recent theoretical account, DRYAD, attributes this selective deficit to a global decrease in memory fidelity with age, moderated by weak representation of contextual information. The predictions of DRYAD are tested here in three experiments. We show that an age-related deficit obtains for whichever aspect of the stimulus subjects' attention is directed away from during encoding (Experiment 1), suggesting a central role for attention in producing the age-related deficit in context. We also show that an analogous deficit can be elicited within young subjects with a manipulation of study time (Experiment 2), suggesting that any means of reducing memory fidelity yields an interaction of the same form as the age-related effect. Experiment 3 evaluates the critical prediction of DRYAD that endorsement probability in an exclusion task should vary nonmonotonically with memory strength. This prediction was confirmed by assessing the shape of the forgetting function in a continuous exclusion task. The results are consistent with the DRYAD account of aging and memory judgments and do not support the widely held view that aging entails the selective disruption of processes involved in encoding, storing, or retrieving contextual information.     

Development of classification: The use of similarity and dimensional relations

Findings about perceptual development indicate that overall similarity is the primary perceptual relation by which young children compare complex objects. Traditional studies of classification, however, did not focus on children's organizational use of holistic relations but rather on their ability to classify by dimensions or criterial attributes. The results from such traditional studies suggest that young children are deficient classifiers. The present research investigated the possibility, contrary to the traditional view, that 4- to 6-year-old children are competent and systematic classifiers at least by overall similarity. In three experiments, preschoolers and kindergarteners classified various sets of multidimensional stimuli that could be organized into categories by overall similarity or by dimensional attributes. Consistent with the research in perceptual development, the children were highly attentive to overall similarity. However, the preschoolers in particular showed marked difficulty in using this relation to form categories of more than two objects. The children's difficulties were highly reminiscent of traditional claims about early classification. Analyses of the classification strategies used by the children, however, suggest that even the youngest children understood the purpose of a classification. The developmentla changes appear to be in the ability to execute a classification. Importantly, type of classification strategy was independent of type of category organization. Individual children used the same strategies both when classifying by overall similarity and by dimensional attributes. These results strongly suggest that it is the classification skills themselves, and not just the ability to classify by particular relations, that change with age.     

Choice of conflict-handling strategy: a matter of context

In this study, a follow-up to Callanan and Perri (2006), the authors investigated whether individuals are inclined to choose a conflict-handling approach based on their primary orientation as given by a standardized instrument, or whether they choose a style different from their primary orientation. The authors also assessed whether individuals are inclined to choose the appropriate or "optimal" strategy as based on contextual factors embodied in the conflict situation. Participants in the study were 184 graduate and undergraduate students from two universities located in the United States. Results show that when individuals are presented with conflict scenarios based on real-life events, they can and do choose conflict-handling strategies that are different from their presumed dominant strategy. Further, results show that individuals are generally able to read contextual factors and social cues to select the most "situationally appropriate" conflict-handling response. This study presents implications for future research and discusses issues related to the management of interpersonal and intragroup conflict.     

Repetition priming mediated by task similarity in semantic classification

In the present study, the specificity of repetition priming between semantic classification tasks was examined using Osgood's (Osgood, Suci, & Tannenbaum, 1957) semantic space as a heuristic for determining the similarity between classifications. The classification tasks involved judging the meaning of words on semantic scales, such as pleasant/unpleasant. The amount of priming across classifications was hypothesized to decrease with increasing distance (decreasing similarity) between semantic scales in connotative semantic space. The results showed maximum repetition priming when the study and the test classifications were the same, intermediate degrees of priming when the study and the test classification scales shared loadings on semantic factors, and little priming when the study and the test classification scales loaded primarily on orthogonal semantic factors--that is, when the distance between scales was maximized. Consistent with the transfer-appropriate processing framework, repetition priming in semantic classifications was highly task specific, decreasing with increasing distance between classification scales.     

Silence in context: Ethnomethodology and social theory

Ethnomethodologists (or at least many of them) have been reticent about their theoretical sources and methodological principles. It frequently falls to others to make such matters explicit. In this paper I discuss this silence about theory, but rather than entering the breach by specifying a set of implicit assumptions and principles, I suggest that the reticence is consistent with ethnomethodology's distinctive research 'program'. The main part of the paper describes the pedagogical exercises and forms of apprenticeship through which Garfinkel and Sacks aimed to develop ethnomethodology as a practice. These efforts were not entirely successful, partly because ethnomethodological 'practice' required an engagement with other fully-fledged practices. Aside from the difficulties of mastering such practices, it was unclear what an ethnomethodological study would add to, or take from, them. Whether successful or not, ethnomethodological research points to the specificity of discourse and action in any given practice which a general theory is bound to misconstrue. Current disputes about cultural constructivist versions of natural science illustrate the problems that arise when the terms of a general theory are used to describe and evaluate specific domains of practice. The paper concludes by recommending ethnomethodology as a way to dissolve an unbridgeable gap between cultural theories and socially located practices.     

Subitizing and similarity: Toward a pattern-matching theory of enumeration

Pattern-matching theories of subitizing claim that subjects enumerate displays with small numerosities by retrieving numerical responses associated with similar displays experienced in the past. Such retrieval implies that displays with small numerosities are similar to other displays of the same numerosity and dissimilar to other displays of different numerosities. These hypotheses were tested by having subjects rate the similarities of displays of dot patterns with numerosities in the range of 1-10. One group of subjects rated patterns of the same numerosity. Their ratings were higher for patterns in the subitizing range (numerosities of 1-3) than for patterns beyond the subitizing range (numerosities of 4-10). Another group rated patterns of different numerosities. Their ratings were lower in the subitizing range than beyond the subitizing range. An analysis based on multidimensional scaling suggested that numerosity could be retrieved accurately for displays of 1-3 dots, but not for displays of 4-10 dots.