Many previous investigations have relied on entries in encyclopedias or similar sources (e.g., Who's Who) to quantify eminence and achievement. The premises in these earlier studies have been that eminence is a function of reputation and that reputation is accurately captured by encyclopedias and the like. In this article, the authors examine reputational changes from era to era. They expected that a comparison of encyclopedias from different eras would show significant changes, with some eminent persons having reputations (or at least biographical entries) that increase, some having reputations that decrease, and others having stable reputations. Can such change (or stability) be reliably assessed and predicted? To address these questions, encyclopedia entry length from 1911 was compared to encyclopedia entry length from 2002, using 1,004 individuals selected in a previous biographical study. Regression analysis indicates that biographical entries did in fact change significantly. The authors also explore implications for definitions of eminence and for the quantification of reputation.