1. Introduction and Overview. 2. Detecting Influential Observations and Outliers. 3. Detecting and Assessing Collinearity. 4. Applications and Remedies. 5. Research Issues and Directions for Extensions. Bibliography. Author Index. Subject Index.

Regression Diagnostics: Identifying Influential Data and Sources of Collinearity

The package “adehabitat” for the R software: A tool for the analysis of space and habitat use by animals

本文对国际科学计量学杂志《Ｓｃｉｅｎｔｏｍｅｔｒｉｃｓ》１９７９－１９９１年的研究论文内容、栏目、作者及国别和编委及国别作了计量分析，揭示出科学计量学研究的重点、活动的中心及发展趋势，说明了学科带头人在发展科学计量学这门新兴学科中的作用。

国际刊物《Scientometrics》文献计量研究

The underrepresentation of women at the top of math-intensive fields is controversial, with competing claims of biological and sociocultural causation. The authors develop a framework to delineate possible causal pathways and evaluate evidence for each. Biological evidence is contradictory and inconclusive. Although cross-cultural and cross-cohort differences suggest a powerful effect of sociocultural context, evidence for specific factors is inconsistent and contradictory. Factors unique to underrepresentation in math-intensive fields include the following: (a) Math-proficient women disproportionately prefer careers in non–math-intensive fields and are more likely to leave math-intensive careers as they advance; (b) more men than women score in the extreme math-proficient range on gatekeeper tests, such as the SAT Mathematics and the Graduate Record Examinations Quantitative Reasoning sections; (c) women with high math competence are disproportionately more likely to have high verbal competence, allowing greater choice of professions; and (d) in some math-intensive fields, women with children are penalized in promotion rates. The evidence indicates that women’s preferences, potentially representing both free and constrained choices, constitute the most powerful explanatory factor; a secondary factor is performance on gatekeeper tests, most likely resulting from sociocultural rather than biological causes.

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Women's underrepresentation in science: sociocultural and biological considerations.

A review of the literature on citation impact indicators

Impact factor is a quasi-qualitative indicator, which provides a measurement of the prestige and international visibility of journals. Although the use of impact factor-based indicators for science policy purposes has increased over the last two decades, several limitations have been pointed out and should be borne in mind. The use of impact factor should be treated carefully when applied to the analysis of peripheral countries, whose national journals are hardly covered by ISI databases. Our experience in the use of impact factor based indicators for the analysis of the Spanish scientific production is shown. The usefulness of the impact factor measures in macro, meso and micro analyses is displayed. In addition, the main advantages, such as the great accessibility of impact factor and its ready-to-use nature are pointed out. Several limitations such as the need to avoid inter-field comparisons or the convenience of using a fixed journal set for international comparisons are also stressed. It is worth noting that the use of impact factor in the research evaluation process has influenced strongly the publication strategy of scientists.

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Advantages and limitations in the use of impact factor measures for the assessment of research performance

Interdisciplinarity is considered the best way to face practical research topics since synergy between traditional disciplines has proved very fruitful. Studies on interdisciplinarity from all possible perspectives are increasingly demanded. Different interdisciplinarity measures have been used in case studies but, up to now, no general interdisciplinarity indicator useful for Science Policy purposes has been accepted. The bibliometric methodology presented here provides a general overview of all scientific disciplines, with special attention to their interrelation. This work aims to establish a tentative typology of disiciplines and research areas according to their degree of interdisciplinarity. Interdisciplinarity is measured through a series of indicators based on Institute for Scientific Information (ISI) multi-assignation of journals in subject categories. Research areas and categories are described according to the quantity of their links (number of related categories) and their quality (with close or distant categories, diversity, and strength of links). High levels of interrelations between categories are observed. Four different types of categories are found through cluster analysis. This differentiates "big" interdisciplinarity, which links distant categories, from "small" interdisciplinarity, in which close categories are related. The location of specific categories in the clusters is discussed.

Interdisciplinarity in science: a tentative typology of disciplines and research areas

Los estudios bibliometricos tienen por objeto el tratamiento y analisis cuantitativo de las publicaciones cientificas. Forman parte de los «estudios sociales de la ciencia» y entre sus principales aplicaciones se encuentra el area de la politica cientifica. Estos estudios complementan de manera eficaz las opiniones y los juicios emitidos por los expertos de cada area proporcionando herramientas utiles y objetivas en los procesos de evaluacion de los resultados de la actividad cientifica. Sin embargo, dadas las repercusiones que estas evaluaciones tienen sobre la asignacion de fondos para la investigacion e, incluso, la promocion profesional de los investigadores, es necesario conocer bien las caracteristicas de los indicadores bibliometricos y las limitaciones que su uso conlleva. Una de las bases de datos mas utilizada es la del Science Citation Index. En el caso de la investigacion biomedica es util para analizar la produccion cientifica mas visible internacionalmente ya que tiene una buena cobertura de revistas biomedicas pero la investigacion mas clinica y de interes local que se publica en revistas espanolas no esta recogida en la misma. Los indicadores bibliometricos mas utilizados para medir la actividad cientifica se basan en los recuentos de las publicaciones y de las citas recibidas por los trabajos publicados, asi como en el impacto de las revistas de publicacion. El factor de impacto de las revistas es un indicador presente en casi todos los estudios bibliometricos; aunque en ocasiones se equipara alto factor de impacto con mayor calidad, este indicador mide especificamente la visibilidad y la difusion de los trabajos publicados en estas revistas mas que la calidad cientifica de los mismos.

Evaluación de la actividad científica a través de indicadores bibliométricos

Collaboration practices and partners vary greatly per scientific area and discipline and influence the scientific performance. Bibliometric indicators are used to analyse international, domestic and local collaboration in publications of Spanish authors in three Biomedical subfields: Neurosciences, Gastroenterology and Cardiovascular System as covered by theSCI database. Team size, visibility and basic-applied level of research were analysed according to collaboration scope. International collaboration was linked to higher visibility documents. Cluster analysis of the most productive authors and centres provides a description, of collaboration habits and actors in the three subfields. A positive correlation was found between productivity and international and domestic collaboration at the author level.

Local, Domestic and International Scientific Collaboration in Biomedical Research

The ability of g-index and h-index to discriminate between different types of scientists (low producers, big producers, selective scientists and top scientists) is analysed in the area of Natural Resources at the Spanish CSIC (WoS, 1994–2004). Our results show that these indicators clearly differentiate low producers and top scientists, but do not discriminate between selective scientists and big producers. However, g-index is more sensitive than h-index in the assessment of selective scientists, since this type of scientist shows in average a higher g-index/h-index ratio and a better position in g-index rankings than in the h-index ones. Current research suggests that these indexes do not substitute each other but that they are complementary.

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María Bordons

Papers

Advantages and limitations in the use of impact factor measures for the assessment of research performance

Interdisciplinarity in science: a tentative typology of disciplines and research areas

Evaluación de la actividad científica a través de indicadores bibliométricos

Local, Domestic and International Scientific Collaboration in Biomedical Research

Is g-index better than h-index? An exploratory study at the individual level