bluuebunny/crossref_metadata_2025 huggingface dataset:
Initial Failure Analysis of Laminated Composite Plates under Humid Conditions
Authors: Garai Jayanta , Ray Chaitali
Published: July 2005

A quadratic isoparametric finite element formulation based on the first-order shear deformation theory is presented for the initial failure analysis of a laminated composite plate exposed to moist conditions. The moisture concentration causing the failure of composite laminate has been predicted in the present study. An iteration method has been developed for the prediction of moisture concentration for the weakest ply failure of laminated composite plates. Several numerical examples are considered and the results are compared with those available in the published literature. The moisture concentration for the starting of failure has been computed for cross-ply and angle-ply laminations with various boundary conditions, taking into account the moisture independence of the materials properties.
Moisture Effects on Mechanical Performance of Laser-welded Polyamide
Authors: Kagan Val A. , Kocheny Steven A. , Macur John E.
Published: July 2005

Basic experimental investigations, in our case of polyamide at ‘dry-as-molded conditions’, include optical examination and mechanical performance for through transmission laser welding technology. Recent developments on laser welding of thermoplastics for automotive powertrain applications have discussed the influence of accumulated moisture on the optical and mechanical characteristics of laser welded polyamide. Results from this report provide supporting data that moisture in polyamides is not a barrier for laser welding applications, nor is detrimental for the mechanical performance of welded parts in automotive powertrain applications. Laser welding would be able to satisfy and support the basic demands of the mechanical performance of welded polyamide at various environmental and manufacturing conditions. This can only be achieved at optimized processing and weld design conditions.
Anti-Communist Justice and Founding the Post-Communist Order: Lustration and Restitution in Central Europe
Authors: Appel Hilary
Published: July 2005

This article explores how ideas and beliefs shaped the development of programs of retrospective justice. By focusing on lustration, property restitution, and the declassification of secret service files in four central European countries, this article investigates the role of formalized anti-communist programs in the founding of the new political and economic order. After reviewing the development of anti-communist programs in East Germany, the Czech Republic, Poland, and Hungary, the article examines the motivation behind these programs and the variation in approaches across countries. It then analyzes the implications of anti-communist programs for the creation of a post-communist national identity, and concludes with a discussion of the weak anti-communist programs in post-Soviet Russia.
Developing child-care provision in England and Germany: problems of governance
Authors: Evers Adalbert , Lewis Jane , Riedel Birgit
Published: July 2005

Both the UK and German governments have sought to expand child-care provision. There is some evidence of convergence between the two countries in respect of changes in governance as well, but we suggest that the differences remain more striking. The paper draws on national-level data and local case-studies in both countries. We comment on the nature of the expansion of child care and, briefly, on the degree of commitment to it, before exploring the operation of the mixed economy of child care in each country and the relationship between local and central government. We seek the explanation for the differences we observe in the articulation between these two key modes of governance.
The European Social Model: an exercise in deconstruction
Authors: Jepsen Maria , Serrano Pascual Amparo
Published: July 2005

One of the fastest growing European catchwords at the present time - the ‘European Social Model’ (ESM) - is used to describe the European experience of simultaneously promoting sustainable economic growth and social cohesion. The use of the concept of ESM in academic and political debate is characterized by two main and interconnected features: on the one hand, the usually taken-for-granted assumption of the reality of the concept (the reality called ‘Europe’ becomes a naturally occurring phenomenon); on the other hand, the highly ambiguous and polysemic nature of this concept. A clear definition of what constitutes its essence seems to be lacking in most documents on the subject, while a review of some of the most important of these documents reveals that, insofar as definitions are to be found, they do not necessarily converge. This article aims to discuss the concept of the ESM. It analyses and deconstructs the concept in order to identify the main understandings and the various dimensions of the model. It classifies and discusses the ways in which the ESM is most frequently construed and proposes a new approach to understanding this polysemy. We argue that the different dimensions of the concept can be seen as rhetorical resources intended to legitimize the politically constructed and identity-building project of the EU institutions.
Information literacy
Authors: Lloyd Annemaree
Published: July 2005

This article reports on doctoral research which explored the meaning and role of information literacy among a specific group of workers - firefighters. An alternative concept of information literacy and a broader definition of information literate people are introduced. The article suggests that librarians are currently bound by an educational concept of what information literacy is and how it manifests itself. They must begin to engage with and explore other contexts and practices that facilitate becoming information literate, in order to understand the role of information literacy in learning outside educational settings. By engaging with different contexts, concepts and truths, our provision of information literacy education will be enhanced and contribute towards learning practices which are transformative, generic and transferable.
Small Amplitude Plane Waves in Deformed Mooney—Rivlin Viscoelastic Solids
Authors: Saccomandi Giuseppe
Published: July 2005

A homogeneous isotropic incompressible viscoelastic material of differential type whose elastic part of the stress tensor is modelled through the use of the Mooney—Rivlin from of the stored energy function, and whose dissipative part is modelled as in a Newtonian fluid, is maintained in a state of finite static homogeneous biaxial deformation. The equations of superimposed infinitesimal motions on the finite deformation are derived. All propagating homogeneous and inhomogeneous solutions are given, as well as the conditions for linear, elliptical, or circular polarization.
Finite-Amplitude Damped Inhomogeneous Waves in a Deformed Blatz-Ko Material
Authors: Ferreira E. Rodrigues , Boulanger Ph.
Published: July 2005

In this paper special Blatz-Ko nonlinear elastic materials are considered, which are characterized by a constitutive constant and a constitutive function. We deal with the propagation of finite-amplitude inhomogeneous plane waves in such materials subjected to an arbitrary static homogeneous deformation. Linearly polarized transverse “damped” inhomogeneous plane wave solutions are explicitly obtained. Such waves are attenuated (or amplified) both in space and time (time-harmonic inhomogeneous plane waves obtained previously by Destrade appear as a special case). The properties of the energy flux vector and energy density associated with these wave solutions are investigated. With an appropriate concept of mean, it is seen that the “mean” energy-flux vector and the “mean” energy density satisfy two relations which are independent of the constitutive constant and constitutive function of the model, and of the homogeneous static deformation of the material. These relations are the same as those obtained by Hayes in the general context of time-harmonic inhomogeneous plane waves in linear systems. However, here, the theory is nonlinear, and the finite-amplitude waves are not time-harmonic.
Finite-Amplitude, Shockless, Resonant Vibrations of an Inhomogeneous Elastic Panel
Authors: Mortell Michael P. , Seymour Brian R.
Published: July 2005

An inhomogeneous, nonlinear elastic panel, fixed at one end, is subject to a resonant harmonic forcing at the other. The vibrations in an equivalent homogeneous panel would contain shocks. We exhibit a class of finite inhomogeneities that produces a panel response that is harmonic but does not contain shocks. The finite-strength inhomogeneity is capable of inhibiting the nonlinear distortion sufficiently to prevent shocks from forming. This is not the case for a “slow” inhomogeneity that can be described using a geometrical acoustics approximation.
Hammering of Nails and Pitons
Authors: Villaggio Piero
Published: July 2005

Hammering nails into timber is amongst the oldest techniques, but understanding the accompanying mechanics is difficult. We here suggest simple models that explain the penetration of a nail into a small hole or narrow crack. The fixing of nails into cracks is also now common in mountaineering both to aid safety and to facilitate climbing.
Examining Attributes of Homicides
Authors: Safarik Mark E. , Jarvis John P.
Published: July 2005

The empirical value of traditional measures related to homicide, the cause of death, and weapon use are well researched and documented in the literature. This research proposes new scale measures quantifying the degree of injury exhibited in homicide cases that can be used to further examine the dynamics of homicidal behavior. These scales are then tested in an examination of a limited set of data reflecting homicides of elderly women. Normally the purview of trauma studies, where the use of injury scales to assess patient survivability is known, homicidal injury is examined using a similar method as a means for exploring offender and crime scene variables. As proposed here, these injury scales may also prove to be useful in furthering other areas of homicide research.
Homicide in Seattle’s Chinatown, 1900-1940
Authors: Paciotti Brian
Published: July 2005

This study extends the understanding of how features of Chinese social organization influenced patterns of homicide in Seattle from 1900 to 1940. The findings illustrate that generalizations about Chinese violence fit pre–World War II Seattle homicide data: (a) Chinese homicide rates were high as a result of conflict between tong organizations involved in the vice industry; (b) the timing of tong events was driven by disputes among organizational chapters in different cities; and (c) homicide rates unrelated to tong violence were relatively low but far higher than modern Asian rates. The findings suggest the importance of considering patterns of violence within particular ethnic groups to evaluate how ethnic social organizations influence violence.
Transactions vs. Relationships: What Should the Company Emphasize?
Authors: Fruchter Gila E. , Sigué Simon P.
Published: July 2005

The relevance of transactional and relational marketing variables in relational exchanges is now well established in the marketing literature. However, the knowledge about their relative effectiveness and their optimal mix over time remains very sparse. An analytical model is proposed to help determine optimal decision rules for transactional and relational marketing efforts. Some of the main results are as follows: (a) If the seller benefits from the interaction between the transactional marketing effort and buyer’s commitment, then the seller’s optimal decision rules change over time and depend on the level of the partners’commitment. (b) Otherwise, the seller’s optimal decision rules for the two types of marketing are constant over time. (c) The seller should allocate more resources to relational marketing at the beginning of a relational exchange and, later on, should allocate more resources to transactional marketing.
Selecting Profitable Customers for Complex Services on the Internet
Authors: Vroomen Björn , Donkers Bas , Verhoef Peter C. , Franses Philip Hans
Published: July 2005

In contrast to books and compact discs, the number of complex services offered on the Internet is still small. The decision-making process for complex services is different because it has an additional intermediate step of “indication of interest.” The Web site is (a) visited and searched for information; subsequently, (b) a request for the service is made, which may lead to (c) a purchase. The authors acquired a unique data set from an online Dutch financial service provider, which offers services such as mortgage loans and insurance on the Internet on behalf of financial institutions. They also obtained information on whether the request for the service resulted in a purchase. The authors used the available information to predict the purchase using a latent class probit model. A direct managerial application of this model is the ability to identify and select profitable applicants, resulting in significant profit improvements for the company.
Postswitching Negative Word of Mouth
Authors: Wangenheim Florian v.
Published: July 2005

Previous research has extensively studied the determinants of customer loyalty and switching behavior but has given little attention to what happens after a customer has switched away from a service provider. In this article, the perhaps most important manifestation of such postswitching behavior—namely, postswitching negative word of mouth (PNWOM)—is investigated. Drawing from dissonance theory, hypotheses are developed and tested in an empirical study. Results from the telecommunications industry indicate that PNWOM is given frequently and that product involvement, market mavenism, perceived risk, satisfaction with the new provider, and the reason for switching the provider explain PNWOM. Implications for customer management are discussed.
Postcard From NYC October 2004
Authors: Ironstone-Catterall Penelope
Published: July 2005

This “theoretical postcard” emerged out of the author’s curious uneasiness both before and after a trip to New York City for a conference on psychoanalysis and democracy in the weeks just before the 2004 American presidential election. In the wake of this uneasiness and occasioned by the work of afterthought, the author asks questions about the desires and fantasies of both democracy and psychoanalysis in the aftermath of traumatic perception. Drawing a parallel between the spaces of New York City and Abu Ghraib prison, this theoretical postcard interrogates the idea of democracy in trauma, insisting on its central place in critically assessing the limits and liabilities of liberal democracies. It draws on the overdeterminations of New York City in televisual discourse as well as on the photographic “visibility” of the carceral in Abu Ghraib prison to ask, What does democracy want?
Large-Scale Social Experimentation in Britain
Authors: Greenberg David H. , Morris Stephen
Published: July 2005

The Employment Retention and Advancement (ERA) Demonstration programme is a major current welfare-to-work social experiment, the largest random allocation evaluation ever mounted in Great Britain. This article draws on experience gained in designing the ERA Demonstration to explore the strengths and limitations of social experimentation for policy evaluation and analysis. The focus of the discussion is on the reasons for the choice of random allocation as a mean of estimating programme impacts, contrasting this approach with the alternatives. The weaknesses of random allocation designs are also examined in the light of the types of information policy-makers require from evaluations of labour market programmes and social policy demonstrations. The perennial ‘black box’ problem and the difficulties in generalizing from social experiments are given particular prominence.
OECD Environmental Performance Review Programme
Authors: Lehtonen Markku
Published: July 2005

The growing interest in evaluation as a new form of environmental governance stems from two developments: the movement towards New Public Management, and the search for new policy instruments for managing complexity, uncertainty and plurality of values in the pursuit of sustainable development. The former holds increasing accountability as the main purpose of evaluation, while the latter stresses the importance of learning. These approaches are often considered as mutually exclusive, but recent literature has underlined their complementary roles in policy making. This article examines to what extent the OECD Environmental Performance Review (EPR) programme has succeeded in combining the objectives of learning and accountability within a single evaluation framework. The EPRs have been relatively successful in avoiding the negative side-effects often associated with traditional performance measurement, but have usually failed to generate broad debate. Focusing on enhancing accountability through social learning would probably contribute to overcoming this problem.
The Practice and the Theory
Authors: Mackenzie Mhairi , Blamey Avril
Published: July 2005

Theory-based evaluation approaches are becoming increasingly popular in the evaluation of comprehensive community initiatives. Such an approach, Theory of Change (ToC), has been used in the external evaluations of two of four Scottish Health Demonstration projects. This article provides an empirically based analysis of the issues raised in the process of articulating a project’s ToC. It then considers the value of the approach in relation to sharpening planning, providing formative feedback, improving performance management, guiding internal and external evaluation, judging impact and reducing problems of attribution. A conclusion is reached that, whilst such approaches are by no means a panacea, they offer one useful framework within which to negotiate a range of evaluation practice decisions.
Use of Aid Evaluation from an Organizational Perspective
Authors: Schaumburg-Müller Henrik
Published: July 2005

The evaluation of foreign aid is thoroughly integrated into the work of aid agencies. It is argued that evaluations contribute to organizational learning and are used to support change in policies and operations. How the use of evaluation is understood, however, depends on the organization perspective applied. Various organization perspectives are relevant. This article discusses the different approaches and looks at organizational practices and a number of case studies to address the question of how evaluation is used. The findings suggest that the use of evaluation for learning in agencies may be less important than other inputs, and evaluation results only partly support policy and operational changes. One single perspective on an organization cannot explain its evaluation processes and use. Different elements of the evaluation appear to be dominated by specific organization perspectives.
Speaking for Others: The Pros and Cons of Group Advocates using Collective Language
Authors: Hornsey Matthew J. , Blackwood Leda , O’brien Anne
Published: July 2005

We examined how rhetorical style affects evaluations of group advocates, and how these evaluations are moderated by group identification. University students were given a letter to the editor defending student welfare. The argument was either constructed using personal language (‘I believe’) or collective language (‘we believe’). Furthermore, the letter was either attributed to an official advocate (president of the student union) or an unofficial advocate (a rank-and-file member of the student body). Consistent with the social identity perspective, participants who showed strong identification as a university student thought that the group would feel better represented by official advocates using collective rather than personal language. Low identifiers, however, did not rate the rhetorical styles differently on representativeness. Furthermore, low identifiers (but not high identifiers) rated official advocates as more likable and more effective when they used personal rather than collective language. The discussion focuses on the conflict low identifiers might feel between (a) needing to homogenize with other group members in order to maximize the influence and political effectiveness of their message at the collective level, and (b) protecting themselves against categorization threat.
Left high and dry?
Authors: Sampson Helen
Published: July 2005

Drawing on fieldwork conducted in India, this article explores the lives of women married to seafarers from Mumbai and Goa, charting the changes in attitudes, values and daily life that can be seen as resulting from their husbands’ occupations. Using their own words and accounts and working through their own grounded experiences and changed circumstances, the article describes how despite, and sometimes because of, the isolation imposed upon seafarers’ wives, many have developed an independence that is recognized and often celebrated by family members but is also regarded as unusual within their local contexts. Additionally, access to higher incomes allows many seafarers and their partners to make significant choices about their domestic living arrangements which are not available to others working in the local economy.
Private security and urban crime mitigation
Authors: Vindevogel Franck
Published: July 2005

This article identifies Business Improvement Districts (BIDs) as new actors of urban policing and analyzes the relatively unknown contribution of their security divisions to public safety. Over the past two decades, property owners and corporate leaders in hundreds of business districts across the United States have banded together to change people’s negative perceptions about downtown. Contrary to all appearances, BIDs have not established a private crimefighting force, but instead have strived to eliminate all signs of physical and behavioral disorders to prevent crime and reassure the public. In doing so, the private sector has implemented the principles of the broken windows theory even before they influenced American policing. This innovative and non-confrontational approach that BIDs have opted for explains why police departments and debt-ridden municipalities have tolerated and sometimes even encouraged the intrusion of private security into public space.
Informal resolution of complaints against the police
Authors: Young Richard , Hoyle Carolyn , Cooper Karen , Hill Roderick
Published: July 2005

In many jurisdictions it is increasingly recognized that police complaints systems should contain a mixture of formal and less formal procedures, as well as allow for a variety of outcomes including remedial and punitive ones. Recent changes to the system for handling complaints against the police in England and Wales envisage an expanded role for local (informal) resolution, with a new range of options including restorative justice conferences. Yet little is known about whether complainants would welcome the option of a restorative justice conference or whether restorative processes would constitute an improvement on conventional practices. This article presents the results of a Nuffield Foundation funded study of these issues carried out in 2002-3 in two police force areas. The findings suggest that restorative processes can achieve moderately better results than conventional processes. While widespread implementation of this new approach is likely to prove problematic for many police services, a flexible approach to introducing changes, drawing on the experience of restorative practitioners in related areas, is likely to benefit complainants without creating dissatisfaction among police officers.
Was the 1937 U.S. Housing Act a Pyrrhic Victory?
Authors: Hunt D. Bradford
Published: July 2005

Historians have wrongly portrayed the 1937 Housing Act, which established a permanent public housing program in the United States, as hopelessly compromised by amendments originating from real estate and conservative interests. With a close analysis of the legislative record and archival material, this article argues that most of these amendments originated from divisions among Progressives or from Senator David I. Walsh (D-MA), who wanted to serve the poor and clear slums. The 1937 Housing Act should be viewed as a Progressive bill that weathered the legislative process surprisingly well. Furthermore, public housing’s later struggles cannot be blamed on a law emasculated at its origination. Instead, historians should more carefully examine the implementation of the law as well as its Progressive assumptions.
The End of the Dream: The Political Struggle of America’s Public Housers
Authors: von Hoffman Alexander
Published: July 2005

Public housing in the United States bears little resemblance to the program reformers envisioned in the 1930s. Inspired by European experiments, proponents of public housing dreamed of a decentralized housing program carried out by many entities and aimed at a majority of the population, not the very poor. Before their movement could take root locally, however, the Great Depression created political opportunities for a federal program. Lacking a grassroots constituency, public housers waged a masterful smoke-and-mirrors strategy to stir up support for public housing among nonhousing organizations and, in 1937, won a permanent program. Yet lawmakers used the housers’ antislum arguments to justify including provisions to clear slums and to house the poor and then excluded funds for nongovernmental housing entities such as limited-dividend corporations and cooperatives. The public housing projects themselves would never inspire much political enthusiasm. Thus, the public housers built enough political support to create a public housing program but not to realize their dream.
Physically Distributed Learning: Adapting and Reinterpreting Physical Environments in the Development of Fraction Concepts
Authors: Martin Taylor , Schwartz Daniel L.
Published: July 2005

Five studies examined how interacting with the physical environment can support the development of fraction concepts. Nine‐ and 10‐year‐old children worked on fraction problems they could not complete mentally. Experiments 1 and 2 showed that manipulating physical pieces facilitated children's ability to develop an interpretation of fractions. Experiment 3 demonstrated that when children understood a content area well, they used their interpretations to repurpose many environments to support problem solving, whereas when they needed to learn, they were prone to the structure of the environment. Experiments 4 and 5 examined transfer after children had learned by manipulating physical pieces. Children who learned by adapting relatively unstructured environments transferred to new materials better than children who learned with “well‐structured” environments that did not require equivalent adaptation. Together, the findings reveal that during physically distributed learning, the opportunity to adapt an environment permits the development of new interpretations that can advance learning.
On the Experiential Link Between Spatial and Temporal Language
Authors: Matlock Teenie , Ramscar Michael , Boroditsky Lera
Published: July 2005

How do we understand time and other entities we can neither touch nor see? One possibility is that we tap into our concrete, experiential knowledge, including our understanding of physical space and motion, to make sense of abstract domains such as time. To examine how pervasive an aspect of cognition this is, we investigated whether thought about a nonliteral type of motion called fictive motion (FM; as in The road runs along the coast) can influence thought about time. Our results suggest that FM uses the same structures evoked in understanding literal motion, and that these literal aspects of FM influence temporal reasoning.
Cultural Differences in Belief Bias Associated with Deductive Reasoning?
Authors: Unsworth Sara J. , Medin Douglas L.
Published: July 2005

Norenzayan, Smith, Jun Kim, and Nisbett (2002) investigated cultural differences in the use of intuitive versus formal reasoning in 4 experiments. Our comment concerns the 4th experiment where Norenzayan et al. reported that, although there were no cultural differences in accuracy on abstract logical arguments, Koreans made more errors than U.S. undergraduates in judging the logical validity of concrete arguments. Norenzayan et al. concluded that Koreans are less likely than European Americans to decontextualize an argument's content from its logical structure, as Koreans were more likely to consider the believability of the conclusion when assessing an argument's validity (a belief bias). Notably, Korean participants were more conservative (less likely to say an argument is valid) than European American participants when assessing arguments. An analysis of the average of the hit and correct rejection rates in each of the conditions (abstract, concrete–believable, concrete–nonbelievable) revealed that, contrary to conclusions of Norenzayan et al., European Americans were no better than Koreans at determining the validity of concrete deductive arguments with conclusions varying in believability.
Positive Feedback in Hierarchical Connectionist Models: Applications to Language Production1
Authors: Dell Gary S.
Published: July 2005

Recent connectionist models of the perception and production of words make use of positive feedback from later to earlier levels of processing. This paper focuses on production and identifies several specific effects of phoneme‐tomorpheme feedback. In addition, I argue that there is support for the use of this kind of feedback in production from experimental and naturalistic studies of slips of the tongue.
Putting Knowledge in its Place: A Scheme for Programming Parallel Processing Structures on the Fly
Authors: McClelland James L.
Published: July 2005

This paper introduces a mechanism called CID, the Connection Information Distributor. CID extends connectionism by providing a way to program networks of simple processing elements on line, in response to processing demands. Without CID, simultaneous processing of several patterns has only been possible by prewiring multiple copies of the network needed to process one pattern at a time. With CID, programmable processing structures can be loaded with connection information stored centrally, as needed. To illustrate some of the characteristics of the scheme, a CID version of the interactive activation model of word recognition is described. The model has a single permanent representation of the connection information required for word perception, but it allows several words to be processed simultaneously in separate programmable networks. Multiword processing is not perfect, however. The model produces the same kinds of intrusion errors that human subjects make in processing brief presentations of word‐pairs, such as SAND LANE (SAND is often misreported as LAND or SANE). The resource requirements of the mechanism, in terms of nodes and connections, are found to be quite moderate, primarily because networks that are programmed in response to task demands can be much smaller than networks that have knowledge of large numbers of patterns built in.
Representation of Similar Well‐Learned Cognitive Procedures
Authors: Elio Renée
Published: July 2005

Continued practice on a task is characterized by several quantitative and qualitative changes in performance. The most salient is the speed‐up in the time to execute the task. To account for these effects, some models of skilled performance have proposed automatic mechanisms that merge knowlege structures associated with the task into fewer, larger structures. The present study investigated how the representation of similar cognitive procedures might interact with the success of such automatic mechanisms. In five experiments, subjects learned complex, multistep mental arithmetic procedures. These procedures included two types of knowledge thought to characterize most cognitive procedures: “component” knowledge for achieving intermediate results and “integrative” knowledge for organizing and integrating intermediate results. Subjects simultaneously practiced two procedures that had either the same component steps or the same integrative structure. Practiceeffect models supported a procedure‐independent representation for common component steps. The availability of these common steps for use in a new procedure was also measured. Steps practiced in the context of two procedures were expected to show greater transfer to a new procedure than steps learned in the context of a single procedure. This did not always occur. A model using component/integrative knowledge distinction reconciled these results by proposing that integrative knowledge operated on all steps of the procedure: An integral part of the knowledge associated with achieving an intermediate result or state includes how it contributes to later task demands. These results are discussed in the context of automatic mechanisms for skill acquisition.
Integrated Learning: Controlling Explanation
Authors: Lebowitz Michael
Published: July 2005

Similarity‐based learning, which involves largely structural comparisons of instances, and explanation‐based learning, a knowledge‐intensive method for analyzing instances to build generalized schemata, are two major inductive learning techniques in use in Artificial Intelligence. In this paper, we propose a combination of the two methods—applying explanation‐based techniques during the course of similiarity‐based learning. For domains lacking detailed explanatory rules, this combination can achieve the power of explanation‐based learning without some of the computational problems that can otherwise arise. We show how the ideas of predictability and interest can be particularly valuable in this context. We include an example of the computer program UNIMEM applying explanation to a generalization formed using similarity‐based methods.
From Folk Psychology to Naive Psychology
Authors: Clark Andy
Published: July 2005

The notion of folk‐psychology as a primitive speculative theory of the mental is called into question. There is cause to believe that folk‐psychology has more in common with a naive physics than with early speculative physical theorising. The distinction between these is elaborated. The conclusion drawn is that commonsense ascription of psychological content, though not a suitable finishing point for cognitive science, should still provide a more reliable source of data than some contemporary theorists are willing to admit.
Interpretation of Scientific or Mathematical Concepts: Cognitive Issues and Instructional Implications
Authors: Reif Frederick
Published: July 2005

Scientific and mathematical concepts are significantly different from everyday concepts and are notoriously difficult to learn. It is shown that particular instances of such concepts can be identified or generated by different possible modes of concept interpretation. Some of these modes use formally explicit knowledge and thought processes; others rely on less formal case‐based knowledge and more automatic recognition processes. The various modes differ in attainable precision, likely errors, and ease of use. A combination of such modes can be used to formulate an “ideal” model for interpreting scientific concepts both reliably and efficiently. Comparisons are made with the actual concept interpretations of expert scientists and novice students. The discussion elucidates some cognitive and metacognitive reasons why the learning of scientific or mathematical concepts is difficult. It also suggests instructional guidelines for teaching such concepts more effectively.
Why and How to Learn Why: Analysis‐based Generalization of Procedures
Authors: Lewis Clayton
Published: July 2005

Max Wertheimer, in his classic Productive Thinking, linked understanding to transfer: Understanding is important because it provides the ability to generalize the solution of one problem to apply to another. Recent work in human and machine learning has led to the development of a new class of generalization mechanism, called here analysis‐based generalization, which can be used to provide a concrete account of the linkage Wertheimer suggested: these mechanisms all, in different ways, use understanding of examples in the generalization process. In this paper I review this class of mechanism, and describe a method for causal attribution that can produce the analyses of examples that the generalization methods require, in the domain of simple procedures in human‐computer interaction. This causal analysis method is linked with analysis‐based generalization to form EXPL, an implemented model which is a concrete, though limited, instontiation of Wertheimer s scheme. EXPL constructs an understanding of an example procedure and generalizes it on the basis of that understanding. Results of an empirical study suggest that some of EXPL's attribution heuristics are used by people, and that while a subclass of analysis‐based methods, called superstitious methods, seem to provide a more plausible account of people's generalization under the conditions of the study than a contrasting class of rationalistic methods, at least some participants appear to use methods from both classes. The results also show that explanation‐based methods, which rely on comprehensive domain theories, must be used in conjunction with a means for extending the domain theory. If thus enhanced, explanation‐based methods are able to mimic the effects of other analysis‐based methods, and can provide a good account of the data, though combinations of other methods must also be considered. Finally, I return to Wertheimer s ideas to argue that none of the current analysis‐based generalization methods fully captures Wertheimer s notion of understanding. Proper choice among different possible analyses of an example is crucial for Wertheimer, but I argue that this problem may be beyond the reach of learning systems.
A Connectionist Approach to Knowledge Representation and Limited Inference
Authors: Shastri Lokendra
Published: July 2005

Although the connectionist approach has lead to elegant solutions to a number of problems in cognitive science and artificial intelligence, its suitability for dealing with problems in knowledge representation and inference has often been questioned. This paper partly answers this criticism by demonstrating that effective solutions to certain problems in knowledge representation and limited inference can be found by adopting a connectionist approach. The paper presents a connectionist realization of semantic networks, that is, it describes how knowledge about concepts, their properties, and the hierarchical relationship between them may be encoded as an interpreter‐free massively parallel network of simple processing elements that can solve an interesting class of inheritance and recognition problems extremely fast—in time proportional to the depth of the conceptual hierarchy. The connectionist realization is based on an evidential formulation that leads to principled solutions to the problems of exceptions and conflicting multiple inheritance situations during inheritance, and the best‐match or partial‐match computation during recognition. The paper also identifies constraints that must be satisfied by the conceptual structure in order to arrive at an efficient parallel realization.
Observational Learning From Internal Feedback: A Simulation of an Adaptive Learning Method
Authors: Billman Dorrit , Heit Evan
Published: July 2005

Much natural learning occurs by observation without explicit feedback or tutoring, yet few models of learning address this class of tasks. Further, many natural cases of observational learning are complex, and efficient learning seems to demand strategic learning procedures. The present work adopts a design perspective and asks what learning mechanisms would be both useful and feasible for natural induction. Work on closely related learning problems is briefly reviewed and a model for observational rule learning is proposed and simulated. The model extends learning mechanisms developed for explicit learning with feedback to less structured, observational tasks. In particular, the focused sampling mechanism, which is an extension of the attentional learning procedure developed by Zeaman and House (1963), is introduced. The operation of an attentional learning procedure is less clear when extended to learning without feedback, so a simulation was done to evaluate the performance of the model. A series of simulated experiments were run, comparing performance of the learning model with and without the focused sampling component. We evaluated whether and when focused sampling benefits observational learning, investigated the effects of different distributions of systematic and unsystematic features, and compared observational learning to learning with feedback. Results of the simulation suggest that focused sampling does benefit learning, that benefit increases with the complexity of the learning task, and that learning with and learning without feedback exhibit differences in how each is affected by changes in the learning problem. Suggestions about the relation to human data are offered.
Marker Passing as a Weak Method for Text Inferencing
Authors: Norvig Peter
Published: July 2005

The problem of deciding what is implied by a written text, of “reading between the lines” is the problem of text inference. To extract proper inferences from a text requires a great deal of general knowledge on the part of the reader. Past approaches have often used a “strong method” tuned to process a particular kind of knowledge structure (such as a script, or a plan). The alternative is a “weak method” which is applicable to a variety of knowledge structures. Just such a method is proposed here, one which recognizes six very general classes of inference. These classes are not dependent on individual knowledge structures, but instead rely on patterns of connectivity between concepts. Patterns are discovered, and inferences are suggested, by a process of marker passing between concepts.
Race‐Based Parsing and Syntactic Disambiguation
Authors: McRoy Susan Weber , Hirst Graeme
Published: July 2005

We present a processing model that integrates same important psychological claims about the human sentence‐parsing mechanism: namely, that processing is influenced by limitations an working memory and by various syntactic preferences. The model uses time‐constraint information to resolve conflicting preferences in a psychologically plausible way. The starting paint far this proposal is the Sausage Machine model (Fodor & Frazier, 1980: Frazier & Fodor, 1978). From there, we attempt to overcome the original model's dependence an ad hoc aspects of its grammar, and its omission of verb‐frame preferences. We also add mechanisms far lexical disambiguation and semantic processing in parallel with syntactic processing.
Algebra Mal‐Rules and Cognitive Accounts of Error
Authors: Payne Stephen J. , Squibb Helen R.
Published: July 2005

We report an empirical study of elementary algebra errors, conducted in three separate schools. The errors are diagnosed using mal‐rules, as proposed by Sleeman (1984, 1,985). Our analysis uncovers the following properties of algebra mal‐rules: The frequency of mal‐rules is severely skewed, there are many infrequent mal‐rules and few frequent ones; mal‐rules are very unstable, students typically use mal‐rules very irregularly; different mal‐rules have explanatory power in different schools (many of our most powerful mal‐rules are previously unreported); mal‐rule diagnosis Is more successful with more skilled students; students' confidence ratings do not partition the total set of mal‐rules, every mal‐rule we find is associated with high confidence ratings by at least one student. The Implications of our data for cognitive theories of error generation are discussed. Contrary to commonplace assumptions, we argue that It is impossible to make a clear distinction between slips and mistakes; most errors depend on properties of the knowledge base and the cognitive architecture. Errors In a procedural skill cannot be assumed to be purely syntactic In orgin.
Learning Plan Schemata from Observation: Explanation‐Based Learning for Plan Recognition
Authors: Mooney Raymond J.
Published: July 2005

This article discusses how explanation‐based learning of plan schemata from observation can improve performance of plan recognition. The GENESIS program is presented as an implemented system for narrative text understanding that learns schemata and improves its performance. Learned schemata allow GENESIS to use schema‐based understanding techniques when interpreting events and thereby avoid the expensive search associated with plan‐based understanding. Learned schemata also function as new concepts that can be used to cluster examples and index events in memory. In addition, experiments are reviewed which demonstrate that human subjects, like GENESIS, con learn a schema by observing, explaining, and generalizing a single specific instance presented in a narrative.
Combining Social Concepts: The Role of Causal Reasoning
Authors: Kunda Ziva , Miller Dale T. , Claire Theresa
Published: July 2005

Four studies examined how people combine social concepts that have conflicting implications (e.g., Harvard‐educated and carpenter). Several kinds of evidence indicated that such combinations are guided by causal reasoning that draws upon both causal relations contained within the constituent concepts and on broader world knowledge. Open‐ended descriptions of members of combinations contained explicit causal descriptors, as well as emergent attributes not used to describe members of constituents. Ratings of the likelihood that combination members possessed various attributes were not fully predicted by comparable ratings of constituents. Causal reasoning appeared to be most pervasive for combinations viewed as more surprising, suggesting that surprise may have triggered the generation of causal accounts.
Cemented Cup Stability during Lever-Out Testing after Acetabular Bone Impaction Grafting with Bone Graft Substitutes Mixes Containing Morselized Cancellous Bone and Tricalcium Phosphate-Hydroxyapatite Granules
Authors: Arts J J C , Schreurs B W , Buma P , Verdonschot N
Published: July 2005

Bone defects after failed total hip arthroplasty can be reconstructed with impacted morselized bone grafts and a cemented cup. In the near future the amount of bone grafts available for surgical purposes will be insufficient. Ceramic calcium phosphates [tricalcium phosphate (TCP) and hydroxyapatite (HA)] have been widely considered as potential bone graft substitutes or bone graft extenders. In the past, mechanical experiments have been performed to determine implant stability of bone grafts and ceramic TCP-HA granules mixes under a compressive load. However, in-vivo migration studies suggest that shear loading may be equally important. This in-vitro study investigated the initial stability of cups reconstructed with various mixes of bone grafts and ceramic TCP-HA granules in a lever-out situation, where shearing is the predominant loading mode. It was found that the cups reconstructed with mixes of bone graft and TCP-HA granules exhibited greater mechanical stability than the cups reconstructed with bone grafts only. It is concluded that from a mechanical standpoint, when considering shear force resistance, 50–50 per cent volume mix and 25–75 per cent volume mix of morselized cancellous bone graft and TCP-HA granules both provide adequate initial cup stability and can be used for acetabular reconstructions with the bone impaction grafting technique.