Google Scholar Metrics is designed to help authors "gauge the visibility and influence of recent articles in scholarly publications." Towards that goal, Google Scholar Metrics assigns publications a variety of rankings based upon Google's h-index.
H-index is based on h-core, which "is a set of top cited h articles from" a given publication. "The h-median is a measure of the distribution of citations to the h-core articles." Search results display h-index and h-median scores for publications based on the last 5 complete calendar years.
For more information on the methodology and data sources behind the rankings, see Google Scholar Metrics Questions? page.
How to search
Search Scholar Metrics as you would search Google normally, there is only one unified search bar inside the Scholar Metrics section. You enter Scholar Metrics by clicking near the top right of the Google Scholar main page.
Search results for journal name
Below you can see the h-index and h-median rankings for American Sociological Review. Clicking on an h-index score will show the articles which have been cited during the last 5 years.