Threshold values and Boolean retrieval systems

Several papers have appeared that have analyzed recent developments in the problem of processing, in a document retrieval system, queries expressed as Boolean expressions. The purpose of this paper is to continue that analysis. We shall show that the concept of threshold values resolves the problems inherent with relevance weights. Moreover, we shall explore possible evaluation mechanisms for retrieval of documents, based on fuzzy-set-theoretic considerations.     

A general model of query processing in information retrieval systems

Most current document retrieval systems require that user queries be specified in the form of Boolean expressions. Although Boolean queries work, they have flaws. Some of the attempts to overcome these flaws have involved “partial-match” retrieval or the use of fuzzy-subset theory. Recently, some generalizations of fuzzy-subset theory have been suggested that would allow the user to specify queries with relevance weights or thresholds attached to terms. The various query-processing methods are discussed and compared.     

Assessing students' ability to trace matter in dynamic systems in cell biology

College-level biology courses contain many complex processes that are often taught and learned as detailed narratives. These processes can be better understood by perceiving them as dynamic systems that are governed by common fundamental principles. Conservation of matter is such a principle, and thus tracing matter is an essential step in learning to reason about biological processes. We present here multiple-choice questions that measure students' ability and inclination to trace matter through photosynthesis and cellular respiration. Data associated with each question come from students in a large undergraduate biology course that was undergoing a shift in instructional strategy toward making fundamental principles (such as tracing matter) a central theme. We also present findings from interviews with students in the course. Our data indicate that 1) many students are not using tracing matter as a tool to reason about biological processes, 2) students have particular difficulties tracing matter between systems and have a persistent tendency to interconvert matter and energy, and 3) instructional changes seem to be effective in promoting application of the tracing matter principle. Using these items as diagnostic tools allows instructors to be proactive in addressing students' misconceptions and ineffective reasoning.     

The professional engagement model of academic induction into on-line teaching

Current developments in tertiary education settings are resulting in a second wave of academics using on-line technologies in their teaching, providing universities with a considerable professional staff development challenge. The case study presented here illustrates one way of responding to this challenge. Overall, the literature suggests that professional development that is discipline-specific and located in a community-of-practice is more likely to be relevant and productive than a centralized, decontextualized approach. We propose an alternative hybrid model of 'professional engagement' for on-line teaching that attempts to build on existing discipline-specific workplace structures. This includes recruiting academic on-line teaching advisers for each school in the faculty, showcasing existing exemplary practice, and setting up 'professional engagement groups' with a support team. The main advantages of the model are its responsiveness to patterns of academic work and to the immediate needs of academics, the way it enhances the visibility of exemplars of academic work, its cost-effectiveness and scalability, and the complementarity of local and centralized support systems. Limitations include the time needed to build up such staff engagement, an apparent lack of visibility, and difficulty in measuring outcomes.     

A multivariate latent growth curve analysis of adolescent substance use

This article demonstrates a multivariate latent growth curve methodology (LGM) for analyzing longitudinal adolescent substance use data. Hypotheses concerning the form of growth in substance use, individual differences in the common trajectory over time, and covariates influencing growth were tested. Significant linear increases existed for alcohol, cigarette, and marijuana use. Second‐order multivariate extensions of LGM indicated that associations among the individual differences parameters of the various substances could be adequately modeled by a higher order substance use construct. Family status, parent‐child conflict, peer encouragement for substance use, parent substance use, and age significantly influenced initial levels of use. Peer encouragement, change in peer encouragement, change in parent‐child conflict, age, and gender significantly influenced development of use. These findings support the influence of families and peers on the development of adolescent substance use and demonstrate the utility of multivariate extensions of LGM in the analysis of longitudinal data.     

Politics,Paradoxes and Pragmatics of Happiness

European leaders and the popular media have shown a new-found interest in happiness as a socio-political value and goal. A growing body of research attempts to identify the conditions under which humans experience the highest levels of happiness, life-satisfaction or subjective well-being. This essay examines what makes a contemporary science and politics of happiness possible by taking a critical look at such efforts to define, measure and promote happiness, while seeking out a range of diverging, often paradoxical, cultural discourses of happiness. The essay covers the following themes: happiness is attainable; happiness is lost; happiness is obligatory; happiness is impossible; and, happiness is inauthentic. The essay critically examines political uses of the word happiness, disrupting received opinions about this contested term.     

Validation of the swimming competence questionnaire for children

ABSTRACT

Two studies were employed to test the reliability and validity of the Swimming Competence Questionnaire (SCQ) among primary school children. Study 1 was a cross-sectional survey in 4959 primary school children. Study 2 was a pre-post-test quasi-experiment among 1609 primary school children who underwent a 20-lesson learn-to-swim programme. In Study 1, exploratory structural equation modelling revealed excellent goodness-of-fit and scale reliability for a two-factor model comprising distance and skill factors, which supported the construct and convergent validity. SCQ scores were significantly and positively correlated with swimming outcomes (i.e., self-efficacy, intention, swimming frequency), which supported SCQ’s concurrent and criterion validity. Average variance extracted for the SCQ factors exceeded cut-off criteria supporting discriminant validity. In Study 2, pre-test SCQ scores correlated significantly and positively with the SCQ scores, self-efficacy, intention, and swimming frequency at post-test, which supported SCQ’s test-retest reliability and predictive validity. Positive intraclass correlation between SCQ scores and coach ratings at post-test provided evidence for SCQ’s inter-rater reliability. SCQ scores significantly improved at post-test, which supported SCQ’s ecological validity. In conclusion, findings indicate that the SCQ is a valid and reliable measure to assess primary school children’s swimming competence, in terms of swimming distance and basic water survival skills.     

Co-existing Notions of Research Quality: A Framework to Study Context-specific Understandings of Good Research

Minerva - Notions of research quality are contextual in many respects: they vary between fields of research, between review contexts and between policy contexts. Yet, the role of these co-existing...