Four subjects, ecology, applied mathematics, sociology and economics, were selected to assess whether there is a citation advantage between journal articles that have an open access (OA) version on the Internet compared to those articles that are exclusively toll access (TA). In two rounds of data collection, citations were counted using the Web of Science and the OA status of articles was determined by using the search tools OAIster, OpenDOAR, Google and Google Scholar. In the first round a purposive sample of 4633 articles for the four subjects from high impact journals were examined, 2280 (49%) were OA and had a mean citation count of 9.04, whereas the mean for TA articles was 5.76. There was a clear citation advantage for those articles that were OA as opposed to those that were TA. This advantage, however, varied between disciplines, with sociology having the highest citation advantage but the lowest number of OA articles from the sample taken and ecology having the highest individual citation count for OA articles but the smallest citation advantage. Tests of correlation between OA status and a number of variables were generally found to be weak or inconsistent but some associations were significant. Google and Google Scholar were more successful at finding OA articles on the Internet than were OAIster or OpenDOAR. The country of origin of the citing authors for applied maths was found in order to assess whether those authors from poorer countries cited OA articles more frequently than TA articles. While cited to citing article ratios from lower income countries favoured OA articles, overall percentages gave mixed results. The data from the second round confirmed the result for sociology. The second sample for ecology was randomly taken from 82 journals and exhibited a greater OA advantage. For economics, a second purposive sample of articles from 21 mid-range impact journals was taken and also exhibited a greater OA advantage. In an attempt to establish the cause of any citation advantage, logistic regression was used to try to determine whether the bibliographic characteristics of the articles from both rounds could be used to predict OA status. Results from this were generally inconclusive.

Submitted by Alison Vanceto (alison-vanceto@hotmail.com) on 2017-02-17T12:05:18Z No. of bitstreams: 1 DissPRC.pdf: 3774120 bytes, checksum: ac43c623fcb4cf2efe4eaf196a15389d (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2017-03-09T18:40:12Z (GMT) No. of bitstreams: 1 DissPRC.pdf: 3774120 bytes, checksum: ac43c623fcb4cf2efe4eaf196a15389d (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2017-03-09T18:40:30Z (GMT) No. of bitstreams: 1 DissPRC.pdf: 3774120 bytes, checksum: ac43c623fcb4cf2efe4eaf196a15389d (MD5) / Made available in DSpace on 2017-03-09T18:51:50Z (GMT). No. of bitstreams: 1 DissPRC.pdf: 3774120 bytes, checksum: ac43c623fcb4cf2efe4eaf196a15389d (MD5) Previous issue date: 2017-01-16 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / The existence of innumerous barriers to access scientific knowledge gave rise to the movement in favor of open access. The impact of scientific research tends to be measured by the total number of citations the work gets, and so the hypothesis of a possible Open Access Citation Advantage (OACA) emerged, in which it is argued that the articles available in open access have an advantage in the number of citations in relation to those only available in restricted publications. However, assessing the impact of a scientific publication must go beyond the analysis of citations, as it is necessary to consider that scientists do not cite all references that may have influenced them during the research, and that other actors are also part of the scientific community. For these reasons, the use of alternative metrics to assist the evaluation of science has been discussed in a new subfield called Altmetrics. In this sense, the aim of this study was to investigate the potential benefits that open access can offer to the field of Information Science. Therefore, bibliometric citation indicators and altmetric indicators for four journals were collected and analyzed: Journal of the American Society for Information Science, Scientometrics, El Profesional de la Información and Transinformação. Data sources covered Web of Science, Google Scholar, Altmetric.com and Mendeley. The results indicated that open access actually offered advantages over the average number of citations and references in the social web received in all hybrid journals. This fact confirms the validity of the OACA hypothesis for the Information Science area. It was also found that this advantage is maintained, at least, until the eighth year after publication, and it extends to the altmetrics data. / A existência de diversas barreiras de acesso ao conhecimento científico levaram a um movimento em prol do acesso aberto. Como o impacto de uma pesquisa científica costuma ser ponderado pelo número total de citações que o trabalho recebe, surgiu a hipótese do Open Access Citation Advantage (OACA), na qual argumenta-se que os artigos disponibilizados em acesso aberto possuem uma vantagem no número de citações em relação às publicações de acesso restrito. No entanto, avaliar o impacto de uma publicação científica deve ir além da análise de citações, pois é necessário considerar que os cientistas não citam todas as referências que os influenciaram durante a pesquisa e que outros atores também fazem parte da comunidade científica. Por essas razões, a utilização de métricas alternativas que auxiliem a avaliação da ciência vem sendo discutidas em um novo subcampo do conhecimento, chamado Altmetria. Neste sentido, o objetivo deste estudo foi investigar as possíveis vantagens que o acesso aberto pode oferecer ao campo da Ciência da Informação. Para tanto, foram elaborados e analisados indicadores bibliométricos de citação e indicadores altmétricos para quatro periódicos científicos: Journal of the American Society for Information Science, Scientometrics, El Profesional de la Información e Transinformação. As fontes de dados abrangeram a Web of Science, o Google Acadêmico, a Altmetric.com e o Mendeley. Os resultados indicaram que o acesso aberto realmente oferece vantagens em relação ao número médio de citações e de menções na web social recebidas em todas as revistas híbridas, fato que confirma a validade da hipótese de OACA para a área da Ciência da Informação. Verificou-se ainda que essa vantagem se mantém, pelo menos até o oitavo ano após a publicação, e que ela também se estende para os dados altmétricos. / FAPESP: 2015/16872-2