The impact factor (IF) of an academic journal is a measure reflecting the average number of citations to recent articles published in that journal. It is frequently used as a proxy for the relative importance of a journal within its field, with journals with higher impact factors deemed to be more important than those with lower ones. The impact factor was devised by Eugene Garfield, the founder of the Institute for Scientific Information. Impact factors are calculated yearly starting from 1975 for those journals that are indexed in the Journal Citation Reports.
左侧可以设置具体要查看哪个引文体系中的JCR，这里包括Science Edition即SCI和Social Science Edition即SSCI。
在接下来的页面中可以选择具体的主题和排序方式，比如情报学选择Information Science and Library Science。排序方式选择Impact Factor，这样就会按照影响因子从高到低进行排序。