Showing papers in "Scientometrics in 2006"

Theory and practise of the g-index

Abstract: The g-index is introduced as an improvement of the h-index of Hirsch to measure the global citation performance of a set of articles. If this set is ranked in decreasing order of the number of citations that they received, the g-index is the (unique) largest number such that the top g articles received (together) at least g 2 citations. We prove the unique existence of g for any set of articles and we have that g ≥ h. The general Lotkaian theory of the g-index is presented and we show that g = (α-1 / α-2) α-1/α T 1/α where a> 2 is the Lotkaian exponent and where T denotes the total number of sources. We then present the g-index of the (still active) Price medallists for their complete careers up to 1972 and compare it with the h-index. It is shown that the g-index inherits all the good properties of the h-index and, in addition, better takes into account the citation scores of the top articles. This yields a better distinction between and order of the scientists from the point of view of visibility.

Bibliometric monitoring of research performance in the Social Sciences and the Humanities: A review

Abstract: This paper addresses research performance monitoring of the social sciences and the humanities using citation analysis. Main differences in publication and citation behavior between the (basic) sciences and the social sciences and humanities are outlined. Limitations of the (S)SCI and A&HCI for monitoring research performance are considered. For research performance monitoring in many social sciences and humanities, the methods used in science need to be extended. A broader range of both publications (including non-ISI journals and monographs) and citation indicators (including non-ISI reference citation values) is needed. Three options for bibliometric monitoring are discussed.

A Hirsch-type index for journals

Abstract: We suggest that a h-type index - equal to h if you have published h papers, each of which has at least h citations - would be a useful supplement to journal impact factors.

Comparison of the Hirsch-index with standard bibliometric indicators and with peer judgment for 147 chemistry research groups

Abstract: In this paper we present characteristics of the statistical correlation between the Hirsch (h-) index and several standard bibliometric indicators, as well as with the results of peer review judgment. We use the results of a large evaluation study of 147 university chemistry research groups in the Netherlands covering the work of about 700 senior researchers during the period 1991–2000. Thus, we deal with research groups rather than individual scientists, as we consider the research group as the most important work floor unit in research, particularly in the natural sciences. Furthermore, we restrict the citation period to a three-year window instead of ‘life time counts’ in order to focus on the impact of recent work and thus on current research performance. Results show that the h-index and our bibliometric ‘crown indicator’ both relate in a quite comparable way with peer judgments. But for smaller groups in fields with ‘less heavy citation traffic’ the crown indicator appears to be a more appropriate measure of research performance.

Is it possible to compare researchers with different scientific interests

Abstract: The number h of papers with at least h citations has been proposed to evaluate individuals scientific research production. This index is robust in several ways but yet strongly dependent on the research field. We propose a complementary index ) ( 2 T a I N h h = , with ) (T a N being the total number of authors in the considered h papers. A researcher with index hI has hI papers with at least hI citation if he/she had published alone. We have obtained the rank plots of h and h I for four Brazilian scientific communities. In contrast with the h-index, the h I index rank plots collapse into a single curve allowing comparison among different research areas.

Benchmarking scientific output in the social sciences and humanities: The limits of existing databases

Abstract: The goal of this paper is to examine the impact of linguistic coverage of databases used by bibliometricians on the capacity to effectively benchmark the work of researchers in social sciences and humanities. We examine the strong link between bibliometrics and the Thomson Scientific's database and review the differences in the production and diffusion of knowledge in the social sciences and humanities (SSH) and the natural sciences and engineering (NSE). This leads to a re-examination of the debate on the coverage of these databases, more specifically in the SSH. The methods section explains how we have compared the coverage of Thomson Scientific databases in the NSE and SSH to the Ulrich extensive database of journals. Our results show that there is a 20 to 25% overrepresentation of English-language journals in Thomson Scientific's databases compared to the list of journals presented in Ulrich. This paper concludes that because of this bias, Thomson Scientific databases cannot be used in isolation to benchmark the output of countries in the SSH.

On the h-index - : A mathematical approach to a new measure of publication activity and citation impact

Abstract: L'A. analyse les proprietes basiques de l'index-h, indicateur developpe par J. E. Hirsch, sur la base d'un modele de distribution de probabilites largement utilise en bibliometrie, a savoir les distributions Pareto. L'index-h, fonde sur le nombre de citations recues, mesure l'activite de publication et l'impact en citations. C'est un indicateur utile avec d'interessantes proprietes mathematiques, mais qui ne saurait se substituer aux indicateurs bibliometriques courants plus sophistiques.

An informetric model for the Hirsch-index

Abstract: The h-index (or Hirsch-index) was defined by Hirsch in 2005 as the number h such that, for a general group of papers, h papers received at least h citations while the other papers received no more than h citations. This definition is extended here to the general framework of Information Production Processes (IPPs), using a source-item terminology. It is further shown that in each practical situation an IPP always has a unique h-index. In Lotkaian systems h = T 1 / a , where T is the total number of sources and α is the Lotka exponent. The relation between h and the total number of items is highlighted.

Tracking and predicting growth areas in science

Abstract: We explore the possibility of using co-citation clusters over three time periods to track the emergence and growth of research areas, and predict their near term change. Data sets are from three overlapping six-year periods: 1996-2001, 1997-2002 and 1998-2003. The methodologies of co-citation clustering, mapping, and string formation are reviewed, and a measure of cluster currency is defined as the average age of highly cited papers relative to the year span of the data set. An association is found between the currency variable in a prior period and the percentage change in cluster size and citation frequency in the following period. The conflating factor of "single-issue clusters" is discussed and dealt with using a new metric called in-group citation.

Canadian collaboration networks: A comparative analysis of the natural sciences, social sciences and the humanities

Abstract: A basic dichotomy is generally made between publication practices in the natural sciences and engineering (NSE) on the one hand and social sciences and humanities (SSH) on the other. However, while researchers in the NSE share some common practices with researchers in SSH, the spectrum of practices is broader in the latter. Drawing on data from the CD-ROM versions of the Science Citation Index, Social Sciences Citation Index and the Arts & Humanities Citation Index from 1980 to 2002, this paper compares collaboration patterns in the SSH to those in the NSE. We show that, contrary to a widely held belief, researchers in the social sciences and the humanities do not form a homogeneous category. In fact, collaborative activities of researchers in the social sciences are more comparable to those of researchers in the NSE than in the humanities. Also, we see that language and geographical proximity influences the choice of collaborators in the SSH, but also in the NSE. This empirical analysis, which sheds a new light on the collaborative activities of researchers in the NSE compared to those in the SSH, may have policy implications as granting councils in these fields have a tendency to imitate programs developed for the NSE, without always taking into account the specificity of the humanities.

The application of bibliometric analyses in the evaluation of social science research. Who benefits from it, and why it is still feasible

Abstract: The paper discusses an application of bibliometric techniques in the social sciences. While the interest of policy makers is growing, the topic is getting more and more attention from bibliometricians. However, many efforts are put into developing tools to measure scientific output and impact outside the world of the Social Sciences Citation Index, while the use of the SSCI for bibliometric applications is covered with obscurity and myths. This study attempts to clarify some of the topics mentioned against the application of the SSCI for evaluation purposes. The study will cover topics like the existing publication and citation culture within the social sciences, the effect of variable citation windows, and the (geographical) origin of citation flows.

Traces of Prior Art: An analysis of non-patent references found in patent documents

Abstract: The recent developments towards more systemic conceptualizations of innovation dynamics and related policies highlight the need for indicators that mirror the dynamics involved In this contribution, we assess the role that 'non-patent references', found in patent documents, can play in this respect After examining the occurrence of these references in the USPTO and EPO patent systems, their precise nature is delineated by means of a content analysis of two samples of nonpatent references (n=10,000) Our findings reveal that citations in patents allow developing nontrivial and robust indicators The majority of all non-patent references are journal references, which provide ample possibilities for large-scale analyses focusing on the extent to which technological developments are situated within the vicinity of scientific knowledge Application areas, limitations and directions for future research are discussed

Extending citation analysis to non-source items

Abstract: This paper reports the first results of the extension of citation analysis to 'non-source' items, which is one strand of an extensive study of quantitative performance indicators used in the assessment of research. It would be presumptuous to draw firm conclusions from this first foray into the realm of non-source citations, however our analysis is based on an extensive experimental database of over 30,000 publications, so the results can be viewed as strong pointers to possible generalised outcomes. We show that it is possible to mine ISI databases for references to a comprehensive oeuvre of items from whole institutions. Many types of publications are visible in the ISI data - books, book chapters, journals not indexed by ISI, and some conference publications. When applied to the assessment of university departments, they can have a significant effect on rankings, though this does not follow in all cases. The investment of time, effort, and money in a significantly extended analysis will not be equally beneficial in all fields. However, a considerable amount of testing is required to confirm our initial results.

An extension of the Hirsch index: Indexing scientific topics and compounds

Abstract: An interesting twist of the Hirsch index is given, in terms of an index for topics and compounds. By comparing both the hb index and m for a number of compounds and topics, it can be used to differentiate between a new so-called hot topic with older topics. This quick method is shown to help new comers to identify how much interest and work has already been achieved in their chosen area of research.

Science in Brazil. Part 1: A macro-level comparative study

Abstract: In the present paper, the evolution of publication activity and citation impact in Brazil is studied for the period 1991-2003. Besides the analysis of trends in publication and citation patterns and of national publication profiles, an attempt is made to find statistical evidences of the relation between international co-authorship and both research profile and citation impact in the Latin American region. Despite similarities and strong co-publication links with the other countries in the region, Brazil has nonetheless a specific research profile, and forms the largest potential in the region.

On the origins of bibliometrics

Abstract: Among the many statistics on science, called scientometrics, bibliometrics holds a privileged place. Bibliometrics is one of the few subfields concerned with measuring the output side of science. According to most “histories”, bibliometrics owes its systematic development mainly to D.J.D. Price and Eugene Garfield, as founders. The few works conducted before the 1950s are usually relegated to prehistory. This paper documents how the systematic counting of publications originated with psychologists. In the early 1900s, psychologists began collecting statistics on their discipline. Publications came to be counted in addresses, reviews and histories of psychology for several decades. The aim was to contribute to the advancement of psychology. Far from being a negligible output of a prehistoric type, both the volume and the systematicness of these efforts are witnesses to what should be considered as pioneering work, and their authors considered as forerunners to bibliometrics.

Advanced indicators of productivity of universities. An application of robust nonparametric methods to Italian data

Abstract: This paper explores scale, scope and trade-off effects in scientific research and education. External conditions may dramatically affect the measurement of performance. We apply theDaraio&Simar's (2005) nonparametric methodology to robustlytake into account these factors and decompose the indicators of productivity accordingly. From a preliminary investigation on the Italian system of universities, we find that economies of scale and scope are not significant factors in explaining research and education productivity. We do not find any evidence of the trade-off research vs teaching. About the trade-off academic publications vs industry oriented research, it seems that, initially, collaboration with industry may improve productivity, but beyond a certain level the compliance with industry expectations may be too demanding and deteriorate the publication profile. Robust nonparametric methods in efficiency analysis are shown as useful tools for measuring and explaining the performance of a public research system of universities.

A concise review on the role of author self-citations in information science, bibliometrics and science policy

Abstract: The objective of the present study is twofold: (1) to show the aims and means of quantitative interpretation of bibliographic features in bibliometrics and their re-interpretation in research policy, and (2) to summarise the state-of-art in self-citation research. The authors describe three approaches to the role of author self-citations and possible conflicts arising from the different perspectives. From the bibliometric viewpoint we can conclude that that there is no reason for condemning self-citations in general or for removing them from macro or meso statistics; supplementary indicators based on self-citations are, nonetheless, useful to understand communication patterns.

Mapping research topics using word-reference co-occurrences: A method and an exploratory case study

Abstract: Mapping of science and technology can be done at different levels of aggregation, using a variety of methods. In this paper, we propose a method in which title words are used as indicators for the content of a research topic, and cited references are used as the context in which words get their meaning. Research topics are represented by sets of papers that are similar in terms of these word-reference combinations. In this way we use words without neglecting differences and changes in their meanings. The method has several advantages, such as high coverage of publications. As an illustration we apply the method to produce knowledge maps of information science.

Exploring the h-index at the author and journal levels using bibliometric data of productive consumer scholars and business-related journals respectively

Abstract: Using both author-level and journal-level data, Hirsch's h-index is shown to possess substantial heuristic value in that it yields accurate results whilst requiring minimal informational acquisition effort. As expected, the h-index of productive consumer scholars correlated strongly with their total citation counts. Furthermore, the h-indices as obtained via ISI/Thompson and GoogleScholar were highly correlated albeit the latter yielded higher values. Finally, using a database of business-relevant journals, a significant correlation was found between the journals' h-indices and their citation impact scores.

Measuring internationality: Reflections and perspectives on academic journals

Abstract: Internationality as a concept is being applied ambiguously, particularly in the world of academic journal publication. Although different criteria are used by scientometrists in order to measure internationality and to supplement its minimal literal meaning, the present study suggests that no single criterion alone is sufficient. This paper surveys, critically-assesses and extends the existing measures of internationality in the context of academic publishing and identifies those criteria that are most clearly resolved and amenable to quantitative analysis. When applied, however, to a case study of four thematically-connected journals from the field of Health and Clinical Psychology using descriptive statistics and the Gini Coefficient, the measurement of internationality using these criteria was found to be ambiguous. We conclude that internationality is best viewed as a mathematically fuzzy entity and that a single measure Internationality Index, constructed from a combination of suitably weighted criteria, is the only way to unambiguously quantify the degree of internationality.

Collaboration uncovered: Exploring the adequacy of measuring university-industry collaboration through co-authorship and funding

Abstract: Analysing co-authored publications has become the standard way to measure research collaborations. At the same time bibliometric researchers have advised that co-authorship based indicators should be handled with care as a source of evidence on actual scientific collaboration. The aim of this study is to assess how well university-industry collaborations can be identified and described using co-authorship data. This is done through a comparison of co-authorship data with industrial funding to a medical university. In total 436 companies were identified through the two methods. Our results show that one third of the companies that have provided funding to the university had not co-authored any publications with the university. Further, the funding indicator identified only 16% of the companies that had co-authored publications. Thus, both co-authorship and funding indicators provide incomplete results. We also observe a case of conflicting trends between funding and co-authorship indicators. We conclude that uncritical use of the two indicators may lead to misinterpretation of the development of collaborations and thus provide incorrect data for decision-making.

The 'home advantage' effect and patent families. A comparison of OECD triadic patents, the USPTO and the EPO

Abstract: This paper examines the extent of the 'home advantage' effect in the USPTO and the EPO patent data and in the OECD triadic patent families. By comparing a set of internationalisation indicators for a sample of European, US and Japanese MNEs it finds that, contrary to what is often assumed, this effect is not only present in the USPTO but also in the EPO. OECD triadic patent data, instead, are not biased towards any particular home country. It also finds that, because MNEs do not systematically file their patents with the EPO, the USPTO and the JPO, the OECD triadic patent family dataset excludes many patents, especially those invented in the US and accounted for in the USPTO, though it is mainly only low-value patents that are excluded. Thus OECD triadic patents can be considered a satisfactory alternative to the USPTO and the EPO for measuring R&D internationalisation.

Selecting scientific excellence through committee peer review - A citation analysis of publications previously published to approval or rejection of post -doctoral research fellowship applicants

Abstract: We investigated committee peer review for awarding long-term fellowships to post-doctoral researchers as practiced by the Boehringer Ingelheim Fonds (B.I.F.) - a foundation for the promotion of basic research in biomedicine. Assessing the validity of selection decisions requires a generally accepted criterion for research impact. A widely used approach is to use citation counts as a proxy for the impact of scientific research. Therefore, a citation analysis for articles published previous to the applicants' approval or rejection for a B.I.F. fellowship was conducted. Based on our model estimation (negative binomial regression model), journal articles that had been published by applicants approved for a fellowship award (n = 64) prior to applying for the B.I.F. fellowship award can be expected to have 37% (straight counts of citations) and 49% (complete counts of citations) more citations than articles that had been published by rejected applicants (n = 333). Furthermore, comparison with international scientific reference values revealed (a) that articles published by successful and non-successful applicants are cited considerably more often than the “average” publication and (b) that excellent research performance can be expected more of successful than non-successful applicants. The findings confirm that the foundation is not only achieving its goal of selecting the best junior scientists for fellowship awards, but also successfully attracting highly talented young scientists to apply for B.I.F. fellowships.

Measuring the meaning of words in contexts: An automated analysis of controversies about 'Monarch butterflies,' 'Frankenfoods,' and 'stem cells'

Abstract: Co-words have been considered as carriers of meaning across different domains in studies of science, technology, and society. Words and co-words, however, obtain meaning in sentences, and sentences obtain meaning in their contexts of use. At the science/society interface, words can be expected to have different meanings: the codes of communication that provide meaning to words differ on the varying sides of the interface. Furthermore, meanings and interfaces may change over time. Given this structuring of meaning across interfaces and over time, we distinguish between metaphors and diaphors as reflexive mechanisms that facilitate the translation between contexts. Our empirical focus is on three recent scientific controversies: Monarch butterflies, Frankenfoods, and stem-cell therapies. This study explores new avenues that relate the study of co-word analysis in context with the sociological quest for the analysis and processing of meaning.

Science in Brazil. Part 2: Sectoral and institutional research profiles

Abstract: In the present study a bibliometric meso-level analysis of Brazilian scientific research is conducted. Both sectoral and publication profile of Brazilian universities and research institutions are studied. Publication dynamics and changing profiles allow to the conclusion that powerful growth of science in Brazil goes with striking structural changes. By contrast, citation-based indicators reflect less spectacular developments.

Productivity, impact and publication habits by gender in the area of Materials Science

Abstract: A comparative analysis of the scientific performance of male and female scientists in the area of Materials Science at the Spanish Council for Scientific Research (CSIC) is presented. Publications of 333 scientists during 1996-2000 are downloaded from the international database Science Citation Index and the national one ICYT. Scientific performance of scientists is studied through different indicators of productivity (number of SCI and ICYT publications), international visibility (average impact factor of publications, percentage of documents in “top journals”) and publication practices (%international publications, signing order of authors in the documents and different collaboration measures). Inter-gender differences in the research performance of scientists are studied. Influence of professional category and age are analysed. Although women are less productive than men, no significant differences in productivity are found within each professional category. However, a different life-cycle of productivity is found for men and woman and the most important inter-gender differences in productivity occur at the ages of 40-59.

h-index sequence and h-index matrix: Constructions and applications

Abstract: The calculation of Hirsch's h-index is a detail-ignoring way, therefore, single h-index could not reflect the difference of time spans for scientists to accumulate their papers and citations. In this study the h-index sequence and the h-index matrix are constructed, which complement the absent details of single h-index, reveal different increasing manner and the increasing mechanism of the h-index, and make the scientists at different scientific age comparable.

Measuring international research collaboration of peripheral countries: Taking the context into consideration

Abstract: This paper investigates the research collaboration of Korean physicist (1977-2000), using co-authorship method. After discussing on the co-authorship method, this paper suggests the necessity of taking contexts of research collaboration into consideration, especially for scientifically “peripheral”countries. The analysis shows an interesting finding with respect to the international collaboration: the proportion of internationally collaborated papers did not increase substantially during the last two decades, which is against the results of other studies. An analysis of the number of participating countries shows that multilateral collaboration has increased considerably in the last 20 years, though the proportion of international research collaboration remains stable. The results of this study give an indirect support to the transformation of research collaboration from rather 'asymmetrical' from 'symmetrical' one.

Cross-national preference in co-authorship, references and citations

Abstract: The macro-level country-by-country co-authorship, cross-reference and cross-citation analysis started in our previous paper,1 continues with revealing the cross-national preference stucture of the 36 selected countries. Preference indicators of co-authorship, cross-reference and cross-citation are defined, presented and discussed. The study revealed that geopolitical location, cultural relations and language are determining factors in shaping preferences whether in co-authorship, cross-reference or cross-citation. Areas like Central Europe, Scandinavia, Latin America (supplemented with Spain and Portugal), the Far East or the Australia-New Zealand-South Africa triad form typical “clusters” with mutually strong preferences towards each other. The USA appears to have a distinguished role enjoying universal preference, which - in the cross-reference and cross-citation case - is asymmetric for the greater part of the countries under study.