One of the first hurdles in understanding altmetrics is unpacking its designation as an “alternative” to bibliometrics, i.e. metrics derived from the quantitative analysis of scholarly publications, such as citation-based calculations of article and journal influence.
Since the mid-20th century, Impact Factor and citation counts have been the standard means for evaluating the impact of journals and journal articles. More recently, however, we have seen the increasing use of alternative citation-based metrics for journal quality that use different algorithms to rank journals against others in their field, most notably the SCImago Journal Ranking and Source Normalized Impact per Paper (SJR and SNIP) metrics. Even Google Scholar has begun producing its own journal rankings for scholarly disciplines. Read more ….