Science,Society, and Scientific Literacy

Science & Education -     

Farewell

Science & Education -     

Science on the Web: Secondary School Students’ Navigation Patterns and Preferred Pages’ Characteristics

This study aims to explore navigation patterns and preferred pages’ characteristics of ten secondary school students’ searching the web for information about cloning. The students navigated the Web for as long as they wished in a context of minimum support of teaching staff. Their navigation patterns were analyzed using audit trail data software. The characteristics of their preferred Web pages were also analyzed using a scheme of analysis largely based on socio-linguistics and socio-semiotics approaches. Two distinct groups of students could be discerned. The first consisted of more competent students, who during their navigation visited fewer relevant pages, however of higher credibility and more specialized content. The second group consists of weaker students, who visited more pages, mainly of lower credibility and rather popularized content. Implications for designing educational web pages and teaching are discussed.     

Moments generating function of the harmonic mean of two non-identical gamma random variables and its applications in wireless communications

In this paper, a closed-form expression for the moments generating function of the half-harmonic mean of two independent, not necessarily identically distributed gamma random variables with arbitrary parameters is presented. This statistical result is useful to the performance analysis of dual-hop wireless communication systems with amplify-and-forward relays in a Nakagami-m fading environment. The proposed mathematical analysis is substantiated by various numerically evaluated and computer simulation results.     

Charles Darwin and Evolution: Illustrating Human Aspects of Science

Recently, the nature of science (NOS) has become recognized as an important element within the K-12 science curriculum. Despite differences in the ultimate lists of recommended aspects, a consensus is emerging on what specific NOS elements should be the focus of science instruction and inform textbook writers and curriculum developers. In this article, we suggest a contextualized, explicit approach addressing one core NOS aspect: the human aspects of science that include the domains of creativity, social influences and subjectivity. To illustrate these ideas, we have focused on Charles Darwin, a scientist whose life, work and thought processes were particularly well recorded at the time and analyzed by scholars in the succeeding years. Historical facts are discussed and linked to core NOS ideas. Creativity is illustrated through the analogies between the struggle for existence in human societies and in nature, between artificial and natural selection, and between the division of labor in human societies and in nature. Social influences are represented by Darwin’s aversion of criticism of various kinds and by his response to the methodological requirements of the science of that time. Finally, subjectivity is discussed through Darwin’s development of a unique but incorrect source for the origin of variations within species.     

Virtual museums, a survey and some issues for consideration

Museums are interested in the digitizing of their collections not only for the sake of preserving the cultural heritage, but to also make the information content accessible to the wider public in a manner that is attractive. Emerging technologies, such as VR, AR and Web3D are widely used to create virtual museum exhibitions both in a museum environment through informative kiosks and on the World Wide Web. This paper surveys the field, and while it explores the various kinds of virtual museums in existence, it discusses the advantages and limitation involved with a presentation of old and new methods and of the tools used for their creation.     

A goodness of fit test approach in information retrieval

In many probabilistic modeling approaches to Information Retrieval we are interested in estimating how well a document model “fits” the user’s information need (query model). On the other hand in statistics, goodness of fit tests are well established techniques for assessing the assumptions about the underlying distribution of a data set. Supposing that the query terms are randomly distributed in the various documents of the collection, we actually want to know whether the occurrences of the query terms are more frequently distributed by chance in a particular document. This can be quantified by the so-called goodness of fit tests. In this paper, we present a new document ranking technique based on Chi-square goodness of fit tests. Given the null hypothesis that there is no association between the query terms q and the document d irrespective of any chance occurrences, we perform a Chi-square goodness of fit test for assessing this hypothesis and calculate the corresponding Chi-square values. Our retrieval formula is based on ranking the documents in the collection according to these calculated Chi-square values. The method was evaluated over the entire test collection of TREC data, on disks 4 and 5, using the topics of TREC-7 and TREC-8 (50 topics each) conferences. It performs well, outperforming steadily the classical OKAPI term frequency weighting formula but below that of KL-Divergence from language modeling approach. Despite this, we believe that the technique is an important non-parametric way of thinking of retrieval, offering the possibility to try simple alternative retrieval formulas within goodness-of-fit statistical tests’ framework, modeling the data in various ways estimating or assigning any arbitrary theoretical distribution in terms.