The computation of discrimination values

Results have been reported showing the usefulness of discrimination value in automatic construction of dictionaries for information retrieval. While discrimination value is defined in the literature, no specific explanation of its computation is given. In this paper the computation of discrimination value is discussed, a relatively efficient algorithm is presented and an example is given.     

Technical change and social need: the case of high rise flats

The first eleven storey blocks of flats in the UK were built in the early fifties. Only twenty years later over half a million people are housed in blocks varying from eleven to 31 storeys in height. These buildings have been built under the responsibility of public authorities responsible for the provision, management and maintenance of housing. Now, however, the provision of this type of housing has almost come to a halt. The widespread use of high flats has been seen as the inevitable result of advances in building technology. The recent rapid decline in numbers built has been attributed primarily to the concern arising from the inhuman social conditions which must inevitably result from such an unnatural form of housing. This paper argues that while high flats stemmed in part from technological advances, it is not possible to attribute their use to such advances. To do so ignores factors which were at work within national and local government, the building industry and the architectural profession. It is equally insufficient to attribute their decline to social concern. It is more probable that financial pressures and a change in national policy away from new building to restoration of older houses was of greater importance than the social problems created by high flats. However, one factor which helped to unite the various parties responsible for the introduction and use of high flats in housing policy, was a widespread belief in the possibilities of modern technologies in relation to the housing problem. Different aspects of the concept appealed to the different protagonists. This paper briefly describes some of the interactions between the different parties concerned with high flats. The major conclusion is that as an innovation high flats have not conformed to the theoretical postulates expounded about them, and that they have been greatly influenced by existing economic and social structures.     

Environmental jolts, institutional change, and the creation of entrepreneurial opportunity in the US electric power industry

The relationship between institutional change and entrepreneurship is poorly understood. We build the theory in this area by tracing institutional change in the US electric power industry over a 40-year period. Our analysis shows that environmental jolts mobilize actors to reformulate institutions, resulting in increased entrepreneurial opportunity. When the institutional environment is stable, we find that incumbent organizational forms and embedded logics present formidable obstacles to entrepreneurial activity. Environmental jolts, however, catalyze search processes and motivate the evaluation of current institutional logics. Specifically, in the case of the electric power industry, environments of abundance and regulation resulted in homogeneity of organizational structures and strategies, and few entrepreneurial opportunities. Environments marked by scarcity and crisis, however, witnessed heavy scrutiny of existing institutional arrangements that eroded their taken-for-grantedness and symbolic value, resulting in opportunities for entrepreneurial action.     

Universities responding to policy: Organisational change at the University of Namibia

In this article the development of the University of Namibia since itsestablishment (8 years ago) has been studied within the context of theformation of the newly-independent Southern African state of Namibia. Ahybrid framework, based on the major theoretical perspectives ofneo-institutionalism and resource dependency, has been utilized toanalyse the accounts of key respondents involved in these developmentsand hence derive an explanatory narrative of the changes involved inresponse to (government) policy.It is suggested that the major themes within this narrative may be ofexplanatory value when studying organizational change in small(developing) countries with relatively young institutions. Inparticular, the following concepts are worth highlighting: thenormatively strong but operationally weak state interacting with thenormatively weak but operationally strong institution; the commonpolitical elite, with institutional leaders sharing government values;and the relative informality of policy formulation and pluralism ofgovernment, with leading institutional actions having a policy sensingand shaping role.The loose set of themes devised from the interpretation ofsemi-structured interviews with a relatively small number of respondentscan also be considered as providing a conceptual framework for furtherresearch both within the specific institution and on a broadercomparative basis.     

The Future of Professional Photojournalism

The work practices of the professional photojournalist are currently undergoing rapid change in the digital era. New technologies, new platforms and new methods of visual storytelling are exerting a range of pressures and influences that require photojournalists to adapt and respond in different ways. The changes provoke a number of questions that are critical to the future of professional photojournalism: What are the new risks being faced by photojournalists? How are the transformations in the media economy affecting photojournalists’ employment? What does this mean for image quality? How do photojournalists think about the manipulation of images or the staging of events? Given the rise of citizen journalism, digital technology and social media, will there even be professional photojournalists in the future? This paper presents some of the results and new analysis from the first international study into the current state and future of professional photojournalism, with a specific focus on risk and on perceptions of risk among photographers. The results indicate a high degree of risk is experienced among professional photographers with a very strong correlation to the country in which they are based.     

But Does It Work?: The Influence of Presumed Goal Attainment Effectiveness on Willingness to Use Legalistic and Restorative Responses to Offensive Behavior

Although victim-offender conferences (VOCs) ostensibly enable victims to pursue justice goals not achieved through conventional trials, not all victims wish to participate in them. The purpose of this study was to examine how victims’ presumptions regarding the effectiveness of VOCs and trials in accomplishing justice goals influence their willingness to participate in a VOC and their preference for a case to be managed solely by the courts. Study results indicated that participants believed VOCs and trials to be effective at accomplishing different goals and that such influenced how they wanted cases to be managed. This influence was moderated by desires for particular justice goals. These findings have implications for restorative justice researchers and practitioners interested in victims’ motivations to participate in a VOC.     

麦克玛斯特大学"问题学习法"

本文从麦克玛斯特大学“问题学习法”(problern-based learning)实施过程的各个方面：教育目标、教学安排、教学活动、教学评价、教学资源等方面介绍了PBL的教学过程，总结了麦克玛斯特大学PBL课程设置以学生为本，培养学生的学习态度和终身学习的能力以及在教学过程中倡导以生物—心理—社会医学模式培养适合社会发展需要的医生的经验。     

Spatial invariance of handwriting

Two aspects concerning the production of shapes in handwriting are distinguished in the present paper. The first aspect is indicated by thespatial variability of letters measured across replications. Spatial variability is assumed to reflect the basic spatial noise observed in everyday writing. The second aspect deals with the geometric characteristics of letter shapes, measured by the ratio of the vertical over the horizontal letter size (Y/X-ratio). The main question is whether the geometric characteristics and basic spatial noise originate from a common source. More specifically, we are interested in whether Y/X-ratio as well as spatial variability will alter across changed circumstances, or whether Y/X-ratio will alter without a change in spatial variability. Subjects wrote the simple letter sequencelelele in conditions with and without vision under three scaling conditions requirements (small, normal and large letter sizes). The main results were that geometric aspects of letters altered (Y/X-ratio) under no vision and under the scaling requirement to write in a small format. In contrast, shapes were produced with unchanged spatial variability in all conditions of vision and scaling requirements. The results suggest that alterations of geometric aspects of letters across changed circumstances do not necessarily involve an increase in spatial variability.     

Mastery Motivation: Definition and Measurement

This paper presents a working definition of mastery motivation which has evolved from our research with infants and young children over the past two decades. We define mastery motivation as a psychological force that stimulates an individual to attempt independently, in a focused and persistent manner, to solve a problem or master a skill or task which is at least moderately challenging for him or her. After describing key features of this definition, we discuss three conceptual issues: 1) the distinction between mastery motivation and cognitive competence, 2) developmental transitions in mastery motivation, and 3) the breadth of the concept. The paper concludes with a long section on assessing mastery motivation. Persistence at tasks is the main measure of the strength of the child's mastery motivation. Our structured task procedure, for 15- to 36-month-old children, attempts to disentangle mastery motivation and competence. We have also developed a questionnaire to assess mastery motivation in general and in five specific behavioral domains: social, symbolic, combinatorial, means-end, and gross motor. We believe that our definition helps to clarify the concept of mastery motivation and that our assessment procedures will facilitate future research.     

Informational properties of infinite numbers of objects in concurrent discriminations by monkeys

Eight rhesus monkeys were trained on a counterbalanced series of concurrent, two-choice, discrimination tasks that provided different numbers of correct or incorrect objects as lists of discriminanda. Small, large, or infinite lengths of correct or incorrect object lists were combined in different tasks, and acquisition performances were compared. When tasks had an infinite number of objects in their correct list and a small number (4) in their incorrect list, acquisition entailed significantly less error than was seen when a small number of correct objects was paired with an infinite incorrect list. This pattern of outcomes seemed attributable to novelty preference. However, comparison of error distributions from tasks with infinite. list lengths to distributions from analogous tasks with fixed list lengths provided some basis for interpreting the way monkeys integrated information that emerged from the temporally discriminative properties of the tasks. One prospective concern was whether or not these performances represented behaviors like those seen in human cognitive discriminations of frequency of occurrence.