Marketing researchers are interested in the relative persuasiveness of different message modes, such as narratives and arguments. A desire to explicate and compare underlying mechanisms is central to this research, yet progress is hindered by a dearth of measures that can be used meaningfully across modes. In the current project, we identify and validate three cross-modal message perceptions - veracity, novelty, and memorability - that can mediate the relationship between different modes and outcomes. Three studies (Study 1: N = 105; Study 2: N = 322; Study 3: N = 248) confirmed the factor structure, discriminant validity, and cross-modal (narrative vs. argument) value of all three message perceptions. The results of this study provide researchers with three cross-modal measures to support comparative message effects research.