GUEST EDITORIAL: Making and measuring impact in science

The measurement of impact in science is a relatively recent development. For most of human history, there was no reliable method for distinguishing science from non-science, and it was necessary for such method to be developed first. The breakthrough occurred in the 1600s when, facing authoritarian opposition to their respective scientific claims, William Harvey (1578–1657) in England and Galileo Galilei (1564–1642) in Italy side-stepped their opponents by publishing their arguments. As a result, all members of the scholastic community had direct access to their claims and could evaluate them independently. During the fierce controversies that followed, the weight of peer opinion enabled Harvey and Galileo to win. It was in this manner that publication and peer evaluation first emerged as the method—so far the only dependable method—for sorting out science from non-science and for evaluating alternative claims in science. As the practice of publication began to spread, it defined modern science as an open and social activity involving the entire global scientific community.