As part of our ongoing article-level metrics program, we’re delighted to announce that all seven PLoS journals will now provide online usage data for published articles. With this addition, the suite of metrics on PLoS articles now includes measures of: online usage; citations from the scholarly literature; social bookmarks; blog coverage; and the Comments, Notes and ‘Star’ ratings that have been made on the article.
As discussed recently, we at PLoS feel that there is much to be gained from assessing research articles on their own merits rather than on the basis of the journal (and its impact factor) where the work happens to be published. Until recently, however, readers have simply not had suitable tools to give them any indication of the quality (or ‘impact’) of an individual article. With the advent of online publishing and a burgeoning array of third parties providing information on scholarly articles, it has finally become feasible to provide meaningful article-level metrics and indicators for readers.
PLoS has therefore embarked on a program to aggregate a range of available data about an article and place that data on the article itself. The data are found on the new tab called ‘Metrics’, available on all articles. A reader can now scan the various metrics to determine the extent to which the article has been viewed, cited, covered in the media and so forth. With the addition of usage data to the article-level metrics we have taken another step towards providing the community with valuable data that can be used and analyzed.
In order to make article-level metrics as open and useful as possible, we are providing our entire dataset as a downloadable spreadsheet and we encourage interested researchers to download the data and perform their own analyses. We will be updating this spreadsheet periodically, but on launch the data it contains are correct up to July 31st, 2009. Future developments in our article-level metrics program will include the provision of more data for each metric (whenever we can locate high quality sources) and new indicators as they arise, as well as the development of more sophisticated display and analysis tools on the site itself.
We believe that article-level metrics represent an important development for scholarly publishing. While some publishers are providing limited data, we are not aware of any publisher that has gone as far as PLoS in providing such a broad range of indicators and metrics, and in making the data openly available. We invite you to visit our journal sites and seek out the Metrics tab for each article.
It’s also important to emphasize that online usage should not be seen as an absolute indicator of quality for any given article, and such data must be interpreted with caution. To provide additional context and to aid interpretation, we have provided a series of summary tables indicating the average usage of categories of article (grouped by age, journal and topic area). Users will also notice that a number of articles do not have any usage data, because of problems with the log files. We are working hard to add data for these articles, and we also encourage readers to let us know if they find any anomalies or have any questions about the data.
More information about our article-level metrics program can be found in our FAQ, this explanatory website, as well as in this page of descriptive text for each journal (e.g for PLoS Biology and PLoS ONE). We look forward to your feedback, and to further developments in article-level metrics.
Mark Patterson, Director of Publishing
Media and other enquiries to Liz Allen, Director of Marketing, Tel (001) 415 624 1218
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