Lustosa Luiggi Araujo, Chalco Mario Edmundo Pastrana, Borba Cecília de Melo, Higa André Eizo, Almeida Renan Moritz Varnier Rodrigues
Biomedical Engineering Program (Coppe), Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
Sao Paulo Med J. 2012;130(5):314-7. doi: 10.1590/s1516-31802012000500008.
Impact factors are currently the bibliometric index most used for evaluating scientific journals. However, the way in which they are used, for instance concerning the study or journal types analyzed, can markedly interfere with estimate reliability. This study aimed to analyze the citation distribution pattern in three Brazilian journals of general medicine.
This was a descriptive study based on numbers of citations of scientific studies published by three Brazilian journals of general medicine.
The journals analyzed were São Paulo Medical Journal, Clinics and Revista da Associação Médica Brasileira. This survey used data available from the Institute for Scientific Information (ISI) platform, from which the total number of papers published in each journal in 2007-2008 and the number of citations of these papers in 2009 were obtained. From these data, the citation distribution was derived and journal impact factors (average number of citations) were estimated. These factors were then compared with those directly available from the ISI Journal of Citation Reports (JCR).
Respectively, 134, 203 and 192 papers were published by these journals during the period analyzed. The observed citation distributions were highly skewed, such that many papers had few citations and a small percentage had many citations. It was not possible to identify any specific pattern for the most cited papers or to exactly reproduce the JCR impact factors.
Use of measures like "impact factors", which characterize citations through averages, does not adequately represent the citation distribution in the journals analyzed.
影响因子目前是评估科学期刊时最常用的文献计量指标。然而，其使用方式，例如在分析的研究或期刊类型方面，可能会显著干扰评估的可靠性。本研究旨在分析三份巴西普通医学期刊中的引文分布模式。
这是一项基于三份巴西普通医学期刊发表的科学研究的引文数量的描述性研究。
所分析的期刊为《圣保罗医学杂志》《临床》和《巴西医学协会杂志》。本调查使用了科学信息研究所（ISI）平台上的可用数据，从中获取了2007 - 2008年各期刊发表的论文总数以及这些论文在2009年的被引次数。根据这些数据得出引文分布，并估算期刊影响因子（平均被引次数）。然后将这些因子与直接从ISI期刊引证报告（JCR）中获取的因子进行比较。
在所分析的时间段内，这些期刊分别发表了134篇、203篇和192篇论文。观察到的引文分布高度不均衡，即许多论文被引次数很少，而一小部分论文被引次数很多。无法识别被引次数最多的论文的任何特定模式，也无法精确重现JCR影响因子。
使用诸如“影响因子”之类通过平均值来表征引文情况的指标，不能充分代表所分析期刊中的引文分布。
