This chapter discusses the long history of lexical analysis going back to the biblical concordances composed by medieval monks; it highlights the need for sensitivity to semantic shifts over time of one hopes to produce meaningful research using archival text; and it explores how we can apply algorithms to find lexical trends that precisely identify the books and years in which new attitudes appeared, and thus map change over time. Reviewing the errors commonly found in student work, this chapter discusses the danger of automated approaches to textual analysis, and identifies a series of typical errors that it can engender. It then explores how we can rectify these issues with critical thinking, and create the best models for insight. It discusses the use of controlled vocabulary, problematic aspects of keyword searches, and several other nuts and bolts aspect of this research. It also explores the theoretical side, and shows how excellent research is possible if we develop a sensitivity to how language changes, to the multiple layers of meanings beneath words, and to the traditional interpretative questions associated with language.