Do blog citations correlate with a higher number of future citations? Research blogs as a potential source for alternative metrics

Journal-based citations are an important source of data for impact indices. However, the impact of journal articles is not limited to other scholarly material, but extends beyond formal scholarly discourse. Measuring online scholarly impact calls for new indices, complementary to the older ones. In this article, we study a possible alternative metric source, blog posts aggregated at ResearchBlogging.org, which discuss peer-reviewed articles and provide full bibliographic references. Articles reviewed in these blogs therefore receive “blog citations”. We hypothesized that articles receiving blog citations close to their publication time receive more journal citation later on than the articles in the same journal published in the same year that did not receive such blog citations. Statistically significant evidence for articles published in 2009 and 2010 support this hypothesis for 7 out of 12 journals (58%) in 2009 and 13 out of 19 journals (68%) in 2010. Based on these results, we propose blog citations as an alternative metric source.