Clark's Theory Research Articles

Clark theory in the Drury–Arveson space

We extend the basic elements of Clark's theory of rank-one perturbations of backward shifts, to row-contractive operators associated to de Branges–Rovnyak type spaces H(b) contrastively contained in the Drury–Arveson space on the unit ball in Cd. The Aleksandrov–Clark measures on the circle are replaced by a family of states on a certain noncommutative operator system, and the backward shift is replaced by a canonical solution to the Gleason problem in H(b). In addition we introduce the notion of a “quasi-extreme” multiplier of the Drury–Arveson space and use it to characterize those H(b) spaces that are invariant under multiplication by the coordinate functions.

Modeling Agent Interactions using Common Ground Knowledge from a Joint Activity Theory Perspective

Believability is necessary for agents to establish intimate, real-time collaborations with humans in an interactive game environment. In this paper, the authors model sophisticated interaction patterns to improve believability by adapting Herbert Clark's joint activity theory. The authors use virtual basketball as an environment, where many communicative scenarios occur and common ground knowledge of collaborative actions such as passing is necessary. The authors have completed preliminary implementation of the agents through the use of a unique computational model based on common ground, and evaluations of basketball simulations have been made with respect to believability scenarios.

Social Mediating Technologies: Social Affordances and Functionalities

A framework for analyzing computer-mediated communication is presented, based on Clark's theory of common ground. Four technologies are reviewed: Facebook, Wikipedia, Blacksburg Electronic Village, and World of Warcraft, to assess their “social affordances,” that is, how communication is supported and how the technologies provide facilities to promote social relationships, groups, and communities. The technology affordances are related to motivations for use and socio-psychological theories of group behaviour and social relationships. The review provides new insights into the nature of long-lasting conversations in social relationships, as well as how representations of individuals and social networks augment interaction.

An exploration of the impact of computerized patient documentation on clinical collaboration

PurposeThe purpose of this study was to explore the experience of experienced users of computerized patient documentation for the purpose of collaboration and coordination. A secondary analysis of qualitative data using Clark's theoretical framework of communication was conducted with the goal of bringing research findings into design. MethodsPhysicians, nurses and administrative staff volunteered to participate in focus groups at 4 VA sites. Each focus group lasted 1.5h and targeted experience and issues with using computerized documentation. All focus groups were audio-taped and transcribed and submitted to extensive qualitative analysis using ATLAS, iterative identification of concepts and categories. The communication category was targeted for secondary theoretical analysis in order to deepen understanding of the findings. Clark's theory of communication, joint action and common ground heuristics was used to analyze concepts. ResultsKey concepts included: (1) CPD has changed the way that narrative documentation is used in clinical settings to include more communication functions, strategies to establish joint action in both negative and positive ways; (2) functionality added to CPD to increase the efficiency of input may have increased the efficiency of CPD to support shared situation models, joint and action and the establishment of common ground; (3) new usage of CPD may increase tensions between clinical and administrative roles as the role of narrative is re-defined. ConclusionsThis study demonstrates how socio-technical systems co-evolve to support essential human function of coordination and collaboration. Users adapted the system in unique and useful ways that provide insight to future development.

The Quest for Medicines, a Grand Challenge in the Twenty-First Century

The Quest for Medicines, a Grand Challenge in the Twenty-First Century

Phenomenal and Objective Size

Definitions of phenomenal types (Nelson Goodman's definition of qualia, Sydney Shoemaker's phenomenal types, Austen Clark's physicalist theory of qualia) imply that numerically distinct experiences can be type-identical in some sense. However, Goodman also argues that objects cannot be replicated in respect of continuous and densely ordered types. In that case, how can phenomenal types be defined for sizes, shapes and colours, which appear to be continuously ordered types? Concentrating on size, I will argue for the following points. (§2) We cannot deny the possibility of replication in respect of dense types, because this would imply that particulars have determinable sizes, shapes and colours. (§3) Phenomenal sizes and shapes are determinable types; objective, or super-determinate, sizes and shapes are unknowable. (§4) We can define and know, prior to verification, groupings of objective sizes for which indiscriminability is transitive. (§5) Phenomenal identity has to be defined on the basis of these transitive groupings, because finer-grained criteria (such as Goodman's) lead to definition of objective identity. The quality space of phenomenal types consists of overlapping but not dense types, and this prevents a collapse of phenomenal types. 1 .

Using Buyer–Supplier Performance Frontiers to Manage Relationship Performance*

ABSTRACTThis article presents a consensus‐building methodology to implement dyadic performance measurement. It focuses on transmuting supplier performance and buyer performance metrics on several important attributes into actionable relationship management plans using Clark's (1996) theory of performance frontiers. Access to the supplier performance management program of a Fortune 100 corporation was granted to the research team. Direct observation of practice and in‐depth discussions with several managers provided a roadmap for investigating both the literature on quantitative evaluation methods and the empirically derived theory on buyer–supplier relationships from several perspectives. This study describes a multiphase, iterative framework that uses current methods and theory on dyadic buyer–supplier evaluation to consider: (i) evaluation criteria and their importance; (ii) whether the improvement focus should be on strengths, weaknesses, or both; and (iii) whether the referent role supplier should be the ideal supplier, best supplier, or best‐in‐strategic‐group supplier in the focal supply base. We illustrate a unifying approach by reporting results from a large buyer and 35 of its key suppliers. This research makes the case for managing supplier relationships through the dyadic performance lens. The outputs from this framework provide individual supplier improvement paths which are actionable prescriptions for each buyer–supplier dyad, as well as recommendations for strategic group formation.

Staying on the same wavelength: Talking about talking in paediatric speech and language therapy sessions

Participants in speech and language therapy sessions engage in talk about talking to accomplish different social actions: identifying and explaining linguistic concepts; correcting language use; and repairing misunderstanding. Different traditions in interaction research have examined the practices of topic management, correction, and repair in instructional and mundane conversation, but the need to disentangle the common thread of ‘language’ that runs through these practices in speech and language therapy interaction has not been recognized. This paper examines three short extracts from transcripts of clinical interaction involving school‐aged children with language disorders in order to see how they manage communication about metalinguistic topics, in face of the significant difficulties that can arise in the interaction. The analysis builds on the method, techniques, and discoveries made by research in conversation analysis, and, using Clark's theory of language use, proposes an explanatory model of how therapists and children manage their talk about talking.

Common Ground in Electronically Mediated Conversation

Technologies that electronically mediate conversation, such as text-based chat or desktop video conferencing, draw on theories of human−human interaction to make predictions about the effects of design decisions. This lecture reviews the theory that has been most influential in this area: Clark's theory of language use. The key concept in Clark's theory is that of common ground. Language is viewed as a collaborative activity that uses existing common ground to develop further common ground and, hence, to communicate efficiently. The theory (a) defines different kinds of common ground, (b) formalizes the notion of collaborative activity as a “joint action,” and (c) describes the processes by which common ground is developed through joint action. Chapter 1 explains why a purely cognitive model of communication is not enough and what is meant by the phrase “collaborative activity.” Chapter 2 introduces the idea of common ground and how it is used in language through an example of two people conversing over a video link. Chapter 3 indicates where the interested reader can find out about the antecedents to Clark's theory. Chapter 4 sets out the fundamental concepts in Clark's theory. Chapter 5 uses five published case studies of electronically mediated communication to illustrate the value of the theory. These include studies of a computer-supported meeting room (Cognoter), a video tunnel that supports gaze awareness, video conferencing in medical consultation, and text chat.

Local resource competition and the skewness of the sex ratio: a demographic model

Most animal populations are characterized by balanced sex ratios, but there exist several exceptions in which the sex ratio at birth is skewed. An interesting hypothesis proposed by Clark (1978) to explain male-biased sex ratios is the local resource competition theory: the bias may be expected in those species in which males disperse more than females, which are thus more prone to local competition for resources. Here we discuss some of the ideas underlying Clark's theory using a spatially explicit approach. In particular, we focus on the role of spatiotemporal heterogeneity as a possible determinant of biased sex ratios. We model spatially structured semelparous populations where either Ricker density dependence or environmental stochasticity can generate irregular spatiotemporal patterns. The proposed discrete-time model describes both genetic and complex population dynamics assuming that (1) sex ratio is genetically determined, (2) only young males can disperse, and (3) individuals locally compete for resources. The analysis of the model shows that no skewed sex ratios can arise in homogeneous habitats. Temporal asynchronized fluctuations between two distinct patches coupled with dispersal of young males is the minimum requirement for obtaining skewed sex ratios of demographic nature in local adult populations. However, the establishment of a male-biased sex ratio at birth in the long run is possible if dispersal is genetically determined and there is genetic linkage between sex ratio determination and dispersal.

THE COMPARATIVE EFFECTIVENESS OF WEB‐BASED AND CLASSROOM INSTRUCTION: A META‐ANALYSIS

Meta-analytic techniques were used to examine the effectiveness of Web-based instruction (WBI) relative to classroom instruction (CI) and to examine moderators of the comparative effectiveness of the 2 delivery media. The overall results indicated WBI was 6% more effective than CI for teaching declarative knowledge, the 2 delivery media were equally effective for teaching procedural knowledge, and trainees were equally satisfied with WBI and CI. However, WBI and CI were equally effective for teaching declarative knowledge when the same instructional methods were used to deliver both WBI and CI, suggesting media effects are spurious and supporting Clark's (1983, 1994) theory. Finally, WBI was 19% more effective than CI for teaching declarative knowledge when Web-based trainees were provided with control, in long courses, and when trainees practiced the training material and received feedback during training. Study limitations and directions for future research are discussed.

Present Condition on the Problems of the Compilation Process of the Vinaya Materials

At present we do not have a clear understanding of the historical process through which the existing Vinaya materials came into being. One of the most noteworthy points in this field is the difference in structure between Theravada Vinayas and the Mahasamghika Vinaya. It is thought that the compilation process of the Vinaya may be clarified by explaining the reason for this difference. On this point, scholars such as Frauwallner, Hirakawa, Yinshun, Clarke and myself have presented various theories. Clarke's theory, the most recent addition to the discussion, rejects the thesis of Frauwallner's famous work. If Clarke's criticisms are correct, then his interpretation is a revolutionary contribution to the study of the Vinaya. However, there is a serious logical contradiction in Clarke's theory, and therefore Frauwallner's theory cannot be dismissed. In this article, I will outline these past theories and point out the problems in Clarke's work.

Features, places, and things: Reflections on Austen Clark's theory of sentience

Features, places, and things: Reflections on Austen Clark's theory of sentience

Is alignment always the result of automatic priming?

Pickering & Garrod's (P&G's) mechanistic theory of dialogue attempts to detail the psychological processes involved in communication that are lacking in Clark's theory. By relying on automatic priming and alignment processes, however, the theory falters when it comes to explaining much of dialogic interaction. We argue for the inclusion of less automatic, though not completely conscious and deliberate, processes to explain such phenomena.

A Procedure to Calculate Logic Programs by Replacement with the Bodies of Rules and Transformation to Disjunctive Normal Forms

In this paper, we describe the completeness of a calculation procedure of logic programs. The procedure is the combination of two procedures, a replacement procedure of atoms in the goal by the bodies or the negation of the bodies of rules in the program, and a transformation procedure of equations to disjunctive normal forms (DNF) equivalent under Clark's Equational Theory (CET). To combine replacement of atoms in the goal to logical formulae determined from the program and transformation of equations to DNF equivalent under CET is a method by which procedures with the capability of expressing answers in DNF can be build, so it is a leading method for expressing answers in a form including negation. Some procedures based on the method are devised, and their calculation capabilities are shown by applying the theory of completed programs. However, the procedure that uses the bodies or the negation of the bodies of rules for replacement has higher calculation capability, and is intuitively more natural than they. Therefore, to clarify the calculation capability of the procedure is considered an important subject for research into calculation procedures of logic programs with the capability for expressing answers in a form including negation. Moreover, since the completeness is realized by standing on the viewpoint of treating the implication symbol as a different implication symbol from usual, and interpreting logic programs in three-valued logic, examples which support the viewpoint are also described.

On the qualitative approximation of Lipschitzian functions

Problem of topological equivalence between a function and certain local approximations is studied. The study is carried out in a neighbourhood of a critical point with the concept of critical point of Clarke's theory. The function belongs to a particular class of non B-differentiable functions. The local approximations are positively homogeneous maps. Using the concept of topological equivalence we establish the existence of a local coordinate transformation between the original function and the positively homogeneous function. As a consequence we obtain sufficient conditions for the existence of local extremes for the initial map.

AAC Performance and Usability Issues: The Effect of AAC Technology on the Communicative Process

In this article, Clark's theory of language use is applied to the study of conversations of augmented speakers and their addressees. Discussion focuses on how shared meaning—called common ground—is achieved, the process of grounding utterances under real-time constraints, and how the media characteristics of devices affect the grounding process. A joint action analysis of grounding will be applied to examples of word-board and Voice Output Communication Aid (VOCA)-mediated conversations to show how participants organize their talk around specific media constraints to conduct their conversations and solve communication problems. The authors argue that this model of device-mediated communication performance, or some variety of it, has the potential to reconcile many of the individual research findings in this field within a single explanatory framework. If successful, this approach could be used to evaluate future research with an empirically-based model of communication performance.

John Bates Clark's Defense of Mandatory Arbitration and Minimum Wage Legislation

The ideal of Political Economy is not unrestricted competition, but competition that is truly free, because controlled by justice and by law. The distinction between freedom and license needs to be preserved in this department of political philosophy. With that distinction clearly maintained, we may still retain, in economics as in politics, our beautiful watchword, liberty (John Bates Clark 1879, p. 167).John Bates Clark has had a formidable impact on the development of economic theory and the theory of income distribution. In addition, Clark's marginal product theory of distribution has often played an instrumental role in the defense oflaissez-fairepolicies. His theory has been used to criticize a wide variety of market interventions, including minimum wage legislation. As a result it is not surprising that Clark's theory of income distribution, and Clark himself, have drawn more than a few critics.

The Science and Practice of Cognitive Behaviour Therapy

COGNITIVE-BEHAVIOR THERAPY AND THE DIALOGUE OF SCIENCE The Science and Practice of Cognitive Behaviour Therapy D. M. Clark & C. G. Fairburn (Eds.), Oxford, England: Oxford University Press, 1997,437 pp. $47.50 (paperback). D. M. Clark and C. G. Fairburn have edited an extensive and well-documented text that attempts to scientifically ground the practice of cognitive-behavior therapy (CBT). As someone who holds to postmodern leanings, my interaction with this text gave rise to many questions, cautions, and feelings. First, all the contributors to the text succeeded in relating CBT to the scientific method. Second, Clark and Fairburn constructed a text that offered a solid theoretical base for CBT and documented application of the theory to specific clinical problems and disorders. Third, the language of therapy, medicine, pharmacology, and the scientific method led me to question where I might place this book among the many voices vying for attention in the postmodern world. I experienced this book as an important contribution to the modernist postmodernist dialogue. Science and Practice of Cognitive Behaviour Therapy is organized into two parts. The first section comprises five chapters that deal with theory and other general considerations while the second section addresses cognitive-behavior conceptualizations and therapeutic approaches to specific disorders. I will focus primarily on the first section and somewhat touch on the second. As D. M. Clark's preface indicates, the book seeks to link experimental science with the practice of CBT. Part I of the text, entitled "General Considerations," deals with issues that are primarily theoretical in nature. In chapter 1, S. Rachman traces the evolution of CBT. He outlines a historical process that begins with origins of behavior therapy, proceeds to the rise of cognitive therapy, and concludes with a merging of the two. In line with the spirit of the scientific method, Rachman discusses the importance of the empirical tradition within behavioral therapy that was also embraced by cognitive therapy. Rachman envisions a historical, developmental process in which "cognitive therapy [now] provides the content for behavior therapy." Moreover, Rachman offers D. M. Clark's theory of panic disorder as an example of a scientifically viable theory that contains both parsimony and comprehensive explanatory powers of the data pertaining to panic disorder. He concludes the chapter with a discussion of "future trends" and "growth points" where he envisions the need for cognitive reanalyses of specific disorders, linking CBT with neuroscience and a cognitive conceptualization of a wider degree of medical-psychological problems. In the second chapter, M. Gelder explores the scientific foundations for CBT. Gelder structures his chapter around three major areas: (1) the character of key cognitions in psychiatric disorders, (2) predictions concerning the roles of these cognitions, and (3) studies of the factors that maintain cognitions. Gelder believes that for CBT to continually develop, studies must be grounded in clinical as well as normal populations. True to the scientific method, Gelder argues for a move away from broader models of CBT and for a more focused approach based on clinical observations and abnormalities of cognition. Studies of psychopathology from a cognitive perspective would lean on the areas of cognitive science involving thinking, attention, memory, visual imagery, worry, and metacognition. In chapter 3, A. Mathews discusses the role of information-processing in cognition and emotion. In terms of science, Mathews views the information processing model as an important tool because it provides a framework for generating hypotheses and experimental methods for testing them. Mathews delineates the assumptions of the information-processing model, and then goes on to discuss biases in information processing (encoding, interpretation, and memory) as they relate to psychological disorders. …

Generic models of logic programs

The notion of minimal Herbrand models can be generalized to goal-generic models Α, which have the property that P ⊧ ∀(L1 ∧ … ∧ Ln) iff Α ⊧ ∀(L1 ∧ … ∧ Ln), where P is a program and ←L1, …, Ln is a goal. In the first part of this paper we characterize a large class of goal-generic models for definite Horn programs. These are minimal models which satisfy Clark's Equality Theory and which contain an infinite number of ‘unnamed’ elements. Predictably, the situation deteriorates when negation is allowed. There are simple stratified programs like Q = { p(0)←; q(0)←⌝p(x); r(0)→⌝q(0)} with no perfect model Α such that, for all normal goals ←L1, … , Ln, PERF(Q) ⊧ ∀(L1 ∧ … ∧ Ln) iff Α ⊧ ∀(L1 ∧ … ∧ Ln). However, there do exist two models A, B such that PERF(Q) ⊧ ∀(L1 ∧ … ∧ Ln) iff {A,B} ⊧ ∀(L1 ∧ … ∧ Ln, suggesting the conjecture that all stratified programs P have finite goal-generic models sets in PERF(P). In the second part of this paper we show that this conjecture is false. The proof depends on a characterization of model domain elements by way of Cauchy term sequences, a finitary treatment of infinite terms. A model A realizes a Cauchy term sequence T = ‘t1’, εN if there is some element in the domain of Α which is an instance of every term in T, and A omits T otherwise. Basic results from model theory show that the models of Clark's Equality Theory display a rich variety in their realization and omission of Cauchy term sequences. We give a program P which can determine if a model realizes any given computable Cauchy sequence, and show that P is a counterexample to the conjecture.