In research examining the elaboration likelihood model (ELM), argument quality has generally been treated as an expedient methodological tool rather than a conceptually meaningful construct. Differences between strong and weak arguments have typically been cast in terms of pretest results and/or the ad hoc interpretations of researchers. Given the importance of creating effective verbal arguments in marketing communications, a stronger theoretical rationale is needed to establish why, exactly, some verbal arguments are more persuasive than others. Drawing on the literature in logic, social psychology, jurisprudence, and sociolinguistics, this research examines various structural and grammatical elements of verbal arguments in order to develop conceptually meaningful definitions of argument quality and more rigorous theoretical accounts of argument-driven persuasion within the ELM. Several research propositions are derived in order to suggest directions for future research on argument-driven persuasion. © 2003 Wiley Periodicals, Inc.