This paper aims to document the proliferating range of alternatives to the impact factor that have arisen within the past five years, coincident with the increased prominence of open access publishing.
This paper offers an overview of the history of the impact factor as: a measure for scholarly merit; a summary of frequent criticisms of the impact factor's calculation and usage; and a framework for understanding some of the leading alternatives to the impact factor.
This paper identifies five categories of alternatives to the impact factor: measures that build upon the same data that informs the impact factor; measures that refine impact factor data with “page rank” indices that weight electronic resources or web sites through the number of resources that link to them; measures of article downloads and other usage factors; recommender systems, in which individual scholars rate the value of articles and a group's evaluations pool together collectively; and ambitious measures that attempt to encompass the interactions and influence of all inputs in the scholarly communications system.
Librarians can utilize the measures described in this paper to support more robust collection development than is possible through reliance on the impact factor alone.
