Register and the dual nature of functional correspondence: accounting for text-linguistic variation between registers, within registers, and without registers

During the past 20 years, corpus linguistic research on register variation has yielded important theoretical advances. The first part of this paper discusses these advances and the cumulative body of research that has produced them. In the second part of the paper, we focus on the goals of research on register variation. The traditional goal of the text-linguistic (TxtLx) approach to linguistic variation has been to describe registers and patterns of register variation: describing the linguistic and situational characteristics of registers. In this paper, we explore a related, but distinct, text-linguistic goal: to account for all linguistic variation among texts. Because the TxtLx framework assumes the importance of functional correspondence between linguistic characteristics and situational characteristics, it is reasonable to assume that in addition to register, we can use situational parameters coded continuously at the level of individual texts as additional predictors of text-linguistic variation. We describe the results of an empirical study to show that using both register categories and text-level situational parameters as predictors results in a more comprehensive and explanatory model of text-linguistic variation. In the conclusion we discuss the future of corpus-based register studies, focusing on unanswered questions related to theoretical claims about register.