A comparison of two techniques for bibliometric mapping: Multidimensional scaling and VOS

VOS is a new mapping technique that can serve as an alternative to the well-known technique of multidimensional scaling. We present an extensive comparison between the use of multidimensional scaling and the use of VOS for constructing bibliometric maps. In our theoretical analysis, we show the mathematical relation between the two techniques. In our experimental analysis, we use the techniques for constructing maps of authors, journals, and keywords. Two commonly used approaches to bibliometric mapping, both based on multidimensional scaling, turn out to produce maps that suffer from artifacts. Maps constructed using VOS turn out not to have this problem. We conclude that in general maps constructed using VOS provide a more satisfactory representation of a data set than maps constructed using well-known multidimensional scaling approaches

The structural role of the core literature in history

The intellectual landscapes of the humanities are mostly uncharted territory. Little is known on the ways published research of humanist scholars defines areas of intellectual activity. An open question relates to the structural role of core literature: highly cited sources, naturally playing a disproportionate role in the definition of intellectual landscapes. We introduce four indicators in order to map the structural role played by core sources into connecting different areas of the intellectual landscape of citing publications (i.e. communities in the bibliographic coupling network). All indicators factor out the influence of degree distributions by internalizing a null configuration model. By considering several datasets focused on history, we show that two distinct structural actions are performed by the core literature: a global one, by connecting otherwise separated communities in the landscape, or a local one, by rising connectivity within communities. In our study, the global action is mainly performed by small sets of scholarly monographs, reference works and primary sources, while the rest of the core, and especially most journal articles, acts mostly locally

An evaluation of Bradfordizing effects

The purpose of this paper is to apply and evaluate the bibliometric method Bradfordizing for information retrieval (IR) experiments. Bradfordizing is used for generating core document sets for subject-specific questions and to reorder result sets from distributed searches. The method will be applied and tested in a controlled scenario of scientific literature databases from social and political sciences, economics, psychology and medical science (SOLIS, SoLit, USB Köln Opac, CSA Sociological Abstracts, World Affairs Online, Psyndex and Medline) and 164 standardized topics. An evaluation of the method and its effects is carried out in two laboratory-based information retrieval experiments (CLEF and KoMoHe) using a controlled document corpus and human relevance assessments. The results show that Bradfordizing is a very robust method for re-ranking the main document types (journal articles and monographs) in today’s digital libraries (DL). The IR tests show that relevance distributions after re-ranking improve at a significant level if articles in the core are compared with articles in the succeeding zones. The items in the core are significantly more often assessed as relevant, than items in zone 2 (z2) or zone 3 (z3). The improvements between the zones are statistically significant based on the Wilcoxon signed-rank test and the paired T-Test

Does Size Matter? The Multipolar International Landscape of Nanoscience

How do different countries tackle nanoscience research? Are all countries similar except for a trivial size effect, as science is often assumed to be universal? Or does size dictate large differences, as large countries are able to develop activities in all directions of research, while small countries have to specialize in some specific niches? Alternatively, is size irrelevant, as all countries have followed different historical paths, leading to different patterns of specialisation? Here, we develop an original method that uses a bottom-up definition of scientific subfields to map the international structure of any scientific field. Our analysis shows that nanoscience research does not show a universal pattern of specialisation, homothetic of that of a single global leader (e.g., the United States). Instead, we find a multipolar world, with four main ways of doing nanosciences.Fil: Levin, Luciano Guillermo. Universidad Nacional de La Pampa. Facultad de Ciencias Humanas. Instituto de Estudios Sociohistóricos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Jensen, Pablo. École normale supérieure de Lyon; FranciaFil: Kreimer, Pablo Rafael. Universidad Maimónides; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Determinants of the international influence of a R&D organisation: a bibliometric approach

Traditionally, studies on the influence and impact of knowledge-producing organisations have been addressed by means of strict economic analysis, stressing their economic impact to a local, regional or national extent. In the present study, an alternative methodology is put forward in order to evaluate the international scientific impact and influence of a knowledge-producing and -diffusing institution. We introduce a new methodology, based on scientometric and bibliometric tools, which complement traditional assessments by considering the influence of a R&D institution when looking at the scientific production undertaken and the recognition of its relevance by its international peer community. Focusing on the most prolific scientific areas of INESC Porto, and resorting to published scientific work recorded in the Science Citation Index (SCI), we show that INESC Porto has enlarged its international scientific network. The logit estimations demonstrate that the wide geographical influence of INESC Porto scientific research is a result not of its international positioning in terms of co-authorships, but rather a result of the quality of its scientific output.Impact and influence assessment methods; R&D Institutions; Bibliometrics, Scientometrics; knowledge network; INESC Porto

Assessing the influence of R&D institutions by mapping international scientific networks: the case of INESC Porto

Although scientometric and bibliometric studies embrace a much wider perspective of the linkages/networks of R&D institutions than standard economic studies, to the best of our knowledge, these studies have not yet made use of scientometric tools to analyse the influence and impact of R&D institutions. Moreover, the international perspective has so far been neglected both in standard and bibliometric studies. Based on networks of 1239 foreign co-authorships and 13035 foreign citation linkages, we demonstrate that INESC Porto international influence has considerably expanded since 2003, a year that coincided with the implementation of an internal policy of granting monetary prizes to publications in scientific international journals. In terms of co-authorship, the network of INESC Porto more than duplicated (13 countries in the initial period to 27 in 2004-07). In terms of citations, INESC Porto’s network encompassed almost 40 countries during the whole period (1996-2007). Its more prolific units (optoelectronics, energy and multimedia) presented a rather distinct pattern both in terms of size and evolution of the corresponding network boundaries. The network size of foreign co-authorships was not much different between the three units by the beginning of the 2000s (around 10 countries) but it evolved quite distinctly. The most remarkable pattern was registered by the multimedia (UTM) unit, whose network size rose exponentially to 21 countries in 2004-07. This contrasted with the decline (down to 8 countries) of the energy (USE) unit. The citation network of the optoelectronic unit (UOSE) was by far the largest, until 2003, involving 34 distinct countries, which contrasted with the size of USE (12 countries) and UTM (1 country). But again, after 2003, the size of the citation network of USE and UTM converged spectacularly to that of UOSE’s, reaching in the last period 21 and 16, respectively. The influence of INESC Porto reaches all five continents, especially when we consider citation networks. Indeed, excluding the citations from authors affiliated in Portuguese institutions, those that most cite INESC Porto’s (and UOSE’s) works are affiliated in institutions located in China, the UK and the US. The scientific works produced by USE influences mostly authors affiliated in institutions located in India, China and Spain, whereas for UTM the corresponding countries are the US, Germany and Italy. We infer from the evidence analysed that not only did the boundaries of INESC Porto’s scientific network substantially enlarge in the period of analysis (1996-2007) but its ‘quality’ also evidenced a positive evolution, with authors affiliated in institutions located in the scientific frontier countries citing works of INESC Porto (and its units).Bibliometrics, Knowledge networks; R&D Institutions