Showing papers on "Context (language use) published in 1996"

SUS: A 'Quick and Dirty' Usability Scale

Abstract: Usability is not a quality that exists in any real or absolute sense. Perhaps it can be best summed up as being a general quality of the appropriateness to a purpose of any particular artefact. This notion is neatly summed up by Terry Pratchett in his novel Moving Pictures:In just the same way, the usability of any tool or system has to be viewed in terms of the context in which it is used, and its appropriateness to that context. With particular reference to information systems, this view of usability is reflected in the current draft international standard ISO 9241-11 and in the European Community ESPRIT project MUSiC (Measuring Usability of Systems in Context) (e.g. Bevan et al., 1991). In general, it is impossible to specify the usability of a system (i.e. its fitness for purpose) without first defining who are the intended users of the system, the tasks those users will perform with it, and the characteristics of the physical, organizational and social environment in which it will be used.

Software agents: an overview

Abstract: Agent software is a rapidly developing area of research. However, the overuse of the word ‘agent’ has tended to mask the fact that, in reality, there is a truly heterogeneous body of research being carried out under this banner. This overview paper presents a typology of agents. Next, it places agents in context, defines them and then goes on, inter alia, to overview critically the rationales, hypotheses, goals, challenges and state-of-the-art demonstrators of the various agent types in our typology. Hence, it attempts to make explicit much of what is usually implicit in the agents literature. It also proceeds to overview some other general issues which pertain to all the types of agents in the typology. This paper largely reviews software agents, and it also contains some strong opinions that are not necessarily widely accepted by the agent community.

Learning in the presence of concept drift and hidden contexts

Abstract: On-line learning in domains where the target concept depends on some hidden context poses serious problems. A changing context can induce changes in the target concepts, producing what is known as concept drift. We describe a family of learning algorithms that flexibly react to concept drift and can take advantage of situations where contexts reappear. The general approach underlying all these algorithms consists of (1) keeping only a window of currently trusted examples and hypotheses; (2) storing concept descriptions and reusing them when a previous context re-appears; and (3) controlling both of these functions by a heuristic that constantly monitors the system's behavior. The paper reports on experiments that test the systems' perfomance under various conditions such as different levels of noise and different extent and rate of concept drift.

Understanding Practice: Perspectives on Activity and Context

Abstract: Series foreword List of contributors Part I. Introduction: 1. The practice of learning Jean Lave Part II. Learning Craftwork: 2. Learning to navigate Edwin Hutchins 3. Developmental studies of work as a testbench of activity theory: the case of primary care medical practice Yrjo Engestrom 4. Re-searching psychotherapeutic practice Ole Dreier 5. Thinking and acting with iron Charles Keller and Janet Dixon Keller 6. Artificial intelligence as craftwork Lucy A. Suchman and Randall H. Trigg 7. Behavior setting analysis of situated learning: the case of newcomers Urs Fuhrer Part III. Learning as Social Production: 8. Examinations reexamined: certification of students or certification of knowledge? Steinar Kvale 9. Beneath the skin and between the ears: a case study in the politics of representation Hugh Mehan 10. The acquisition of a child by a learning disability R. P. McDermott 11. Context and scaffolding in developmental studies of mother-child problem-solving dyads Harold G. Levine 12. Solving everyday problems in the formal setting: an empirical study of the school as context for thought Roger Saljo and Jan Wynham 13. Teacher's directives: the social construction of 'literal meanings' and 'real worlds' in classroom discourse Norris Minick Part IV. Conclusion 14. Understanding the social scientific practice of Understanding practice Seth Chaiklin Index.

The Ethics of Social Research with Children: An Overview†

Abstract: This paper attempts to provide an overview of ethical issues related to social research with children. It sets the discussion in the context of current debates about researching children in the UK, and explores the extent to which children should be regarded as similar to, or different from, adults in social research, focusing on how children are positioned as vulnerable, incompetent and relatively powerless in society in general, and how this conceptualisation of children needs to be taken into account in social research. The paper concludes with some practical and methodological suggestions.

Making and breaking governments : cabinets and legislatures in parliamentary democracies

Abstract: Series editors' preface Acknowledgements Part I. The Context: 1. Theory, institutions, and government formation 2. The social context of government formation 3. The government formation process Part II. The Model: 4. Government equilibrium 5. Strong parties Part III. Empirical Investigations: 6. Two cases: Germany, 1987 Ireland, 1992-3 7. Theoretical implications, data, and operationalization 8. Exploring the model: a comparative perspective 9. A multivariate investigation of portfolio allocation Part IV. Applications, Extensions, and Conclusions: 10. Party systems and cabinet stability 11. Making the model more realistic 12. Party politics and administrative reform 13. Governments and parliaments Bibliography.

Before Writing: Rethinking the Paths to Literacy

Abstract: Gunther Kress argues for a radical reappraisal of the phenomenon of literacy, and hence for a profound shift in educational practice Through close attention to the variety of objects which children constantly produce (drawings, cuttings-out, 'writings' and collages), Kress suggests a set of principles which reveal the underlying coherence of children's actions; actions which allow us to connect them with attempts to make meaning before they acquire language and writing This book provides fundamental challenges to commonly held assumptions about both language and literacy, thought and action It places these challenges within the context of speculation about the abilities and dispositions essential for children as young adults, and calls for the radical decentring of language in educational theory and practice

Reexamining the cluster hypothesis: scatter/gather on retrieval results

Abstract: We present Scatter/Gather, a cluster-based document browsing method, as an alternative to ranked titles for the organization and viewing of retrieval results. We systematically evaluate Scatter/Gather in this context and find significant improvements over similarity search ranking alone. This result provides evidence validating the cluster hypothesis which states that relevant documents tend to be more similar to each other than to non-relevant documents. We describe a system employing Scatter/Gather and demonstrate that users are able to use this system close to its full potential.

An introductory dictionary of Lacanian psychoanalysis

Abstract: Jacques Lacan's thinking revolutionised the theory and practice of psychoanalysis and had a major impact in fields as diverse as film studies, literary criticism, feminist theory and philosophy. Yet his writings are notorious for their complexity and idiosyncratic style. Emphasising the clinical basis of Lacan's work, An Introductory Dictionary of Lacanian Psychoanalysis is an ideal companion to his ideas for readers in every discipline where his influence is felt. The Dictionary features:* over 200 entries, explaining Lacan's own terminology and his use of common psychoanalytic expressions* details of the historical and institutional context of Lacan's work* reference to the origins of major concepts in the work of Freud, Saussure, Hegel and other key thinkers* a chronology of Lacan's life and works.

Interaction in the Language Curriculum: Awareness, Autonomy and Authenticity

Abstract: Interaction in the Language Curriculum offers an innovative theory of language education integrating curriculum practice, research and teaching It emphasises the interdependence of knowledge and values and stresses the central importance of learning as a social processLeo van Lier argues that moral as well as intellectual and practical principles must underlie curriculum development and everyday teaching, captured in his triple focus on Awareness, Autonomy, and Authenticity In addition to its rich grounding in language education practice, the book draws support for his position from diverse sources in sociology, philosophy and cognitive science, from the work of Bourdieu, Giddens, Wittgenstein, Peirce, Vygotsky, Bakhtin, and Dewey In the current broadening context of language education this study makes an important contribution to research It presents a coherent philosophical theory as well as considering practical issues in implementation of a new language curriculum As such, it will be of great benefit to teachers, applied linguists and educationalists generally

Composite branding alliances : an investigation of extension and feedback effects

Abstract: The authors report two studies investigating the effectiveness of a composite brand in a brand extension context. In composite brand extension, a combination of two existing brand names in differen...

School Context, Principal Leadership, and Student Reading Achievement

Abstract: In this article, we explore the nature and extent of the school principal's effects on reading achievement in a sample of 87 U. S. elementary schools. Our study responded to prior critiques of the literature in school administration by formulating and testing a multidimensional model of principal effects on student learning. By using principal and teacher questionnaires and student test scores, we examined relations between selected school context variables (student SES, parental involvement, principal gender, and teaching experience), principal instructional leadership (principal activity in key dimensions of the school's educational program), instructional climate (school mission, opportunity to learn, teacher expectations), and student reading achievement. Results showed no direct effects of principal instructional leadership on student achievement. The results did, however, support the belief that a principal can have an indirect effect on school effectiveness through actions that shape the school's l...

An event-related potential study of recognition memory with and without retrieval of source

Abstract: Summary Event-related potentials (ERPs) were recorded during the test phase of a recognition memory task in two experiments. In both experiments subjects made initial old/new judgements to visually presented words, and for words judged old, indicated in which of two voices (male/female) the words had been heard at study. In the second experiment only, subjects had the option to signal that they were uncertain about the status of a test word. Two positive-going ERP effects differentiated the ERPs evoked by correctly recognized old worlds from those evoked by words correctly judged new. The two effects differed in their scalp topography and time course, and were both of greater magnitude in the ERPs evoked by recognized words for which a correct voice judgement was made. The findings are consistent with the view that multiple neural systems underlie the ability to recognize an item and to recall its study context. However, the findings offer little support for the view, articulated in certain ‘dual-process’ models of recognition memory, that recognition judgements with and without retrieval of study context depend upon qualitatively different memory processes or systems.

Magnetic relaxation in high-temperature superconductors

Abstract: We review experimental studies of the time decay of the nonequilibrium magnetization in high-temperature superconductors, a phenomenon known as magnetic relaxation. This effect has its origin in motion of flux lines out of their pinning sites due to thermal activation or quantum tunneling. The combination of relatively weak flux pinning and high temperatures leads to rich properties that are unconventional in the context of low temperature superconductivity and that have been the subject to intense studies. The results are assessed from a purely experimental perspective and discussed in the context of present phenomenological theories. [S0034-6861(96)00403-5]

A compact model for speaker-adaptive training

Abstract: We formulate a novel approach to estimating the parameters of continuous density HMMs for speaker-independent (SI) continuous speech recognition. It is motivated by the fact that variability in SI acoustic models is attributed to both phonetic variation and variation among the speakers of the training population, that is independent of the information content of the speech signal. These two variation sources are decoupled and the proposed method jointly annihilates the inter-speaker variation and estimates the HMM parameters of the SI acoustic models. We compare the proposed training algorithm to the common SI training paradigm within the context of supervised adaptation. We show that the proposed acoustic models are more efficiently adapted to the test speakers, thus achieving significant overall word error rate reductions of 19% and 25% for 20K and 5K vocabulary tasks respectively.

Liquid crystals in complex geometries : formed by polymer and porous networks

Abstract: Focusing on the applied and basic aspects of confined liquid crystals, this book provides a current treatise of the subject matter and places it in the broader context of electrooptic applications. The book takes an interdisciplinary approach to the subject, combining basic principles of physics, chemistry, polymer science, materials science and engineering. Key Features:

Clarifying the Entrepreneurial Orientation Construct and Linking it to Performance

Abstract: Clarifies the nature of the entrepreneurial orientation (EO) construct and proposes contingency models for investigating the relationship between EO and firm performance. EO is contrasted to entrepreneurship. Entrepreneurship is new entry. Entrepreneurial orientation is the processes, practices, intentions, and decision-making activities leading to new entry. It has five key dimensions: autonomy, innovativeness, risk taking, proactiveness, and competitive aggressiveness. Although all five dimensions are central to understanding the entrepreneurial process, they occur in different combinations, and the factors vary independently in a given context. Contingency theory suggests that congruence among variables (such as environmental and organizational factors) is crucial for optimal performance; hence the relationship between EO and firm performance is context specific. Key contingencies associated with the relationship between EO and performance are identified. Then four alternative contingency models (moderating, mediating, independent and interaction effects) are proposed for the purpose of testing the relationship of EO and performance. The analysis further delineates various organizational characteristics related to each of the four models that may impact firm performance, including the structure chosen, integrating activities, top management team characteristics and the industry. These characteristics may all affect the five dimensions of entrepreneurial orientation and impact performance. (TNM)

A Predictive Model of Self-Managing Work Team Effectiveness:

Abstract: This paper tests a theoretically-driven model of self-managing work team effectiveness. Self-managing work team effectiveness is defined as both high performance and employee quality of work life. Drawing on different theoretical perspectives including work design, self-leadership, sociotechnical, and participative management, four categories of variables are theorized to predict self-managing work team effectiveness: group task design, encouraging supervisor behaviors, group characteristics, and employee involvement context. Data is collected from both a set of self-managing and traditionally managed teams from a large telephone company, and the model is tested with structural equations modeling. Support is found for hypotheses concerning group task design, group characteristics, and employee involvement context, but not encouraging supervisory behaviors.

Relational aggression, overt aggression, and friendship

Abstract: This study (n = 315 9-12-year-olds) was conducted to assess whether the social problems that relationally and overtly aggressive children typically experience in the peer group context are also exhibited in the dyadic, friendship context The qualities of children's friendships (eg, levels of intimacy) and of the importance of those qualities (eg, the importance of intimacy) were assessed with self-report instruments adapted from past research Results indicated that the friendships of relationally aggressive children were characterized by relatively high levels of intimacy, exclusivity/jealousy, and relational aggression within the friendship context In contrast, the friendships of overtly aggressive children were characterized by engaging together in aggressive acts toward those outside the friendship In addition, overtly aggressive children placed relatively high importance on these coalitional acts and on companionship with their friends Implications for our understanding of aggressive children and for our knowledge of children's friendships are discussed

Context-sensitive learning methods for text categorization

Abstract: Two recently implemented machine-learning algorithms, RIPPER and sleeping-experts for phrases, are evaluated on a number of large text categorization problems. These algorithms both construct classifiers that allow the “context” of a word w to affect how (or even whether) the presence or absence of w will contribute to a classification. However, RIPPER and sleeping-experts differ radically in many other respects: differences include different notions as to what constitutes a context, different ways of combining contexts to construct a classifier, different methods to search for a combination of contexts, and different criteria as to what contexts should be included in such a combination. In spite of these differences, both RIPPER and sleeping-experts perform extremely well across a wide variety of categorization problems, generally outperforming previously applied learning methods. We view this result as a confirmation of the usefulness of classifiers that represent contextual information.

Educational progress of children of immigrants: The roles of class, ethnicity, and school context.

Abstract: Recent immigration to the United States has spawned a rapidly growing second generation, most of whom are of school age. This article reports the findings of a study of 5,266 second-generation high school students in Florida and California, who were children of Cuban and Vietnamese immigrants (representative of relatively advantaged groups) and of Haitian and Mexican immigrants (representative of relatively disadvantaged groups). The study found that parents' socioeconomic status (SES), length of U.S. residence, and hours spent on homework significantly affected the students' academic performance, but did not eliminate the effects of ethnic community. Attendance at higher-SES schools increased the average academic performance and the positive effect of parents' SES, whereas attendance at inner-city schools flattened the negative effect of ethnic disadvantage. However, school context had no appreciable effect on children from advantaged ethnic backgrounds

The Social Psychology of Clothing: Symbolic Appearances in Context

Abstract: CONTENTS Part One: Symbolic Appearances in Context - The Social Psychology of Clothing - Toward a Contextual Perspective - Clothing, Appearance and the Social Construction of Gender Part Two: Appearance and the Self - The Body in Context - Appearance and Self-Concept - Appearance Management and Self-Presentation Part Three: Appearance Communication in Context - The Underlying Context of Appearance - Appearance and Social Cognition - Perceiver Variables - Appearance Commnication: A Two-Way Process Part Four: Appearance and Culture - Appearance in Group and Organisational Culture - Society, Appearance and Fashion - Cultural Categories, Appearances and Social Stratification Part Five: Culture Change and Continuity - Cultural Dynamics and Identity Construction - Fashion Change: Social-Psychological Process in Cultural and Historical Context - Global Influences and Identity Expression Part Six: Symbolic Appearances in Diverse Contexts - Emerging insights, Expanding Possibilities - Clothes, Communities, Identities

The Stick-e Document: a Framework for Creating Context-aware Applications

Abstract: There is increasing interest in computer applications that are aware of the user’s context. Currently these applications are normally hand-crafted. A lot of them consist of presenting information to users as they enter a given context, for example a tourist nearing a site within a city or a visitor moving round a building. The paper presents a new form of document, and the supporting software, which allows such applications to be created simply by building a new document. The motivation is to make the creation and use of these applications as easy as creating and using web pages.

A computational approach to prefrontal cortex, cognitive control and schizophrenia: Recent developments and current challenges

Abstract: In this chapter we consider the mechanisms involved in cognitive control-from both a computational and a neurobiological perspective- and how these might be impaired in schizophrenia. By 'control', we mean the ability of the cognitive system to flexibly adapt its behaviour to the demands of particular tasks, favouring the processing of task-relevant information over other sources of competing information, and mediating task-relevant behaviour over habitual, or otherwise prepotent responses. There is a large body of evidence to suggest that the prefrontal cortex (PFC) plays a critical role in cognitive control. In previous work, we have used a computational framework to understand and develop explicit models of this function of PFC, and its impairment in schizophrenia. This work has lead to the hypothesis that PFC houses a mechanism for representing and maintaining context information. We have demonstrated that this mechanism can account for the behavioural inhibition and active memory functions commonly ascribed to PFC, and for human performance in simple attention, language and memory tasks that draw upon these functions for cognitive control. Furthermore, we have used our models to simulate detailed patterns of cognitive deficit observed in schizophrenia, an illness associated with marked disturbances in cognitive control, and well established deficits of PFC. Here, we review results of recent empirical studies that test predictions made by our models regarding schizophrenic performance in tasks designed specifically to probe the processing of context. These results showed selective schizophrenic deficits in tasks conditions that placed the greatest demands on memory and inhibition, both of which we have argued rely on the processing of context. Furthermore, we observed predicted patterns of deterioration in first episode vs multi-episode patients. We also discuss recent developments in our computational work, that have led to refinements of the models that allow us to simulate more detailed aspects of task performance, such as reaction time data and manipulations of task parameters such as interstimulus delay. These refined models make several provocative new predictions, including conditions in which schizophrenics and control subjects are expected to show similar reaction time performance, and we provide preliminary data in support of these predictions. These successes notwithstanding, our theory of PFC function and its impairment in schizophrenia is still in an early stage of development. We conclude by presenting some of the challenges to the theory in its current form, and new directions that we have begun to take to meet these challenges. In particular, we focus on refinements concerning the mechanisms underlying active maintenance of representations within PFC, and the characteristics of these representations that allow them to support the flexibility of cognitive control exhibited by normal human behaviour. Taken in toto, we believe that this work illustrates the value of a computational approach for understanding the mechanisms responsible for cognitive control, at both the neural and psychological levels, and the specific manner in which they break down in schizophrenia.

Schizophrenic deficits in the processing of context. A test of a theoretical model.

Abstract: Background: Schizophrenic patients show various deficits in cognitive functions that have been difficult to understand in terms of a common unifying hypothesis. Previously described neural network models of cognitive tasks suggest that several schizophrenic performance deficits may be related to a single function—an impairment in maintaining contextual information over time and in using that information to inhibit inappropriate responses. Methods: We tested first-episode schizophrenic patients and patients later in the course of their illness on a new variant of the Continuous Performance Test designed specifically to elicit deficits in the processing of contextual information. Results: Unmedicated schizophrenic patients showed a deterioration of their signal detection performance that followed the pattern predicted by the context hypothesis, ie, they responded inappropriately when correct responding required the maintenance of context information over time to inhibit the expression of a habitual response. This deficit correlated with positive symptoms. The results also suggested that the deficit may be worse in unmedicated patients who have had a longer course of illness. Medicated patients showed a more diffuse performance deficit. Conclusions: These results support the view that a single deficit in the processing of context information may underlie various cognitive impairments observed in schizophrenia. They also suggest that such an impairment is associated with positive rather than negative symptoms, and that it may worsen with the course of the illness as in the kraepelinian view of schizophrenia.

Pseudo‐r2 measures for some common limited dependent variable models

Abstract: A large number of different Pseudo-R2 measures for some common limited dependent variable models are surveyed. Measures include those based solely on the maximized likelihoods with and without the restriction that slope coefficients are zero, those which require further calculations based on parameter estimates of the coefficients and variances and those that are based solely on whether the qualitative predictions of the model are correct or not. The theme of the survey is that while there is no obvious criterion for choosing which Pseudo-R2 to use, if the estimation is in the context of an underlying latent dependent variable model, a case can be made for basing the choice on the strength of the numerical relationship to the OLS-R2 in the latent dependent variable. As such an OLS-R2 can be known in a Monte Carlo simulation, we summarize Monte Carlo results for some important latent dependent variable models (binary probit, ordinal probit and Tobit) and find that a Pseudo-R2 measure due to McKelvey and Zavoina scores consistently well under our criterion. We also very briefly discuss Pseudo-R2 measures for count data, for duration models and for prediction-realization tables.

Visualization of information using graphical representations of context vector based relationships and attributes

Abstract: A system and method for generating context vectors for use in storage and retrieval of documents and other information items. Context vectors represent conceptual relationships among information items by quantitative means. A neural network operates on a training corpus of records to develop relationship-based context vectors based on word proximity and co-importance using a technique of "windowed co-occurrence". Relationships among context vectors are deterministic, so that a context vector set has one logical solution, although it may have a plurality of physical solutions. No human knowledge, thesaurus, synonym list, knowledge base, or conceptual hierarchy, is required. Summary vectors of records may be clustered to reduce searching time, by forming a tree of clustered nodes. Once the context vectors are determined, records may be retrieved using a query interface that allows a user to specify content terms, Boolean terms, and/or document feedback. The present invention further facilitates visualization of textual information by translating context vectors into visual and graphical representations. Thus, a user can explore visual representations of meaning, and can apply human visual pattern recognition skills to document searches.