Impact factors – the basics

Abstract

This chapter is designed to be an introduction to impact factors and how they are calculated. It goes on to look at some of the major issues that need to be considered when evaluating journal impact factors.The chapter considers implications of the cause and effect of subject differences in impact factors and different article types such as news items, editorials and review articles.The paper also considers the skewed distribution of citations to articles within a journal and the relationship between journal size and impact factor changes between years.