Time filter

Source Type

Madrid, Spain

Gomez-Nunez A.J.,SCImago Research Group Associated Unit | Vargas-Quesada B.,University of Granada | de Moya-Anegon F.,Grupo Scimago
Journal of the Association for Information Science and Technology | Year: 2016

This study introduces a new proposal to refine the classification of the SCImago Journal and Country Rank (SJR) platform by using clustering techniques and an alternative combination of citation measures from an initial 18,891 SJR journal network. Thus, a journal–journal matrix including simultaneously fractionalized values of direct citation, cocitation, and coupling was symmetrized by cosine similarity and later transformed into distances before performing clustering. The results provided a new cluster-based subject structure comprising 290 clusters that emerge by executing Ward's clustering in two phases and using a mixed labeling procedure based on tf-idf scores of the original SJR category tags and significant words extracted from journal titles. In total, 13,716 SJR journals were classified using this new cluster-based scheme. Although more than 5,000 journals were omitted in the classification process, the method produced a consistent classification with a balanced structure of coherent and well-defined clusters, a moderated multiassignment of journals, and a softer concentration of journals over clusters than in the original SJR categories. New subject disciplines such as “nanoscience and nanotechnology” or “social work” were also detected, providing evidence of good performance of our approach in refining the journal classification and updating the subject classification structure. © 2015 ASIS&T Source

Guerrero-Bote V.P.,University of Extremadura | Moya-Anegon F.,Grupo Scimago
Proceedings of ISSI 2013 - 14th International Society of Scientometrics and Informetrics Conference | Year: 2013

Download indicators represent a great potential due to the high amount of download data that can be collected that can provide a great statistical significance. The relationship between citation and downloads at journal level and the influence of language on it is studied with the data of Scopus (for citation) and ScienceDirect (for downloads). The results show that the use of downloads as prediction of the citation, is limited, as in the early years is when it obtained less significance. The relationship between downloads and citations is also different in different areas. In Francophone regions the downloads of English language journals is proportionately greatly reduced with respect to their citation. There seems to be a part of the citation impact of the non-English language journals invisible in Scopus, which make the number of downloads proportionally greater than citations. This has its effect on the lack of correlation between the downloads and citations in the non-English language journals. © AIT Austrian Institute of Technology GmbH Vienna 2013. Source

Guerrero-Bote V.P.,University of Extremadura | Moya-Anegon F.,Grupo Scimago
Scientometrics | Year: 2014

Download indicators are of major potential interest because the great quantity of readily available download data means that any statistical inferences drawn from them will be of robust significance. We study the relationship between citation and downloads at the journal and paper levels, and the influence of language on that relationship. The data used were taken from the Scopus (citations) and ScienceDirect (downloads) databases. The results showed that downloads have limited utility as predictors of citation since it is in the early years when any correlations have the least significance. The relationship between downloads and citation also differs from one discipline to another. The relationship at the paper level is considerably weaker than at the journal level. This may be indicative of the number of downloads depending largely on the diffusion of the journal. In francophone regions, downloading from journals is proportionately less than citations to those same journals. There seems to be a part of citations to non-English-language journals which is invisible to Scopus. This makes the number of downloads proportionately greater than that of citations, leading to a lack of correlation between downloads and citations in that class of journal. © 2014 Akadémiai Kiadó, Budapest, Hungary. Source

Olvera-Lobo M.,Grupo Scimago | Olvera-Lobo M.,University of Granada | Gutierrez-Artacho J.,University of Granada
Health Information and Libraries Journal | Year: 2010

Background: Question-answering systems (or QA Systems) stand as a new alternative for Information Retrieval Systems. Most users frequently need to retrieve specific information about a factual question to obtain a whole document.Objectives: The study evaluates the efficiency of QA systems as terminological sources for physicians, specialised translators and users in general. It assesses the performance of one open-domain QA system, START, and one restricted-domain QA system, MedQA.Method: The study collected two hundred definitional questions (What is...?), either general or specialised, from the health website WebMD. Sources used by the open-domain QA system, START, and the restricted-domain QA system, MedQA, were studied to retrieve answers, and later a range of evaluation measures (precision, Mean Reciprocal Rank, Total Reciprocal Rank, First Hit Success) were applied to mark the quality of answers.Results: It was established that both systems are useful in the retrieval of valid definitional healthcare information, with an acceptable degree of coherent and precise responses from both. The answers supplied by MedQA were more reliable that those of START in the sense that they came from specialised clinical or academic sources, most of them showing links to further research articles.Conclusions: Results obtained show the potential of this type of tool in the more general realm of information access, and the retrieval of health information. They may be considered a good, reliable and reasonably precise alternative in alleviating the information overload. Both QA systems can help professionals and users can obtain healthcare information. © 2010 The authors. Health Information and Libraries Journal © 2010 Health Libraries Group. Source

Lancho-Barrantes B.S.,University of Extremadura | Guerrero-Bote V.P.,University of Extremadura | Moya-Anegon F.,Grupo Scimago
Scientometrics | Year: 2010

A study is described of the rank/JIF (Journal Impact Factor) distributions in the high-coverage Scopus database, using recent data and a three-year citation window. It includes a comparison with an older study of the Journal Citation Report categories and indicators, and a determination of the factors most influencing the distributions. While all the specific subject areas fit a negative logarithmic law fairly well, those with a greater External JIF have distributions with a more sharply defined peak and a longer tail-something like an iceberg. No S-shaped distributions, such as predicted by Egghe, were found. A strong correlation was observed between the knowledge export and import ratios. Finally, data from both Scopus and ISI were used to characterize the rank/JIF distributions by subject area. © 2010 Akadémiai Kiadó, Budapest, Hungary. Source

Discover hidden collaborations