Does endorsement rhetoric matter in citizen science?

This study analyzed the influence of rhetoric in the endorsement text on the willingness of the crowd to participate in citizen science projects. Four categories of endorsers were studied: professors, students, industrial researchers, and amateur researchers. Using 1243 endorsement texts from 543 citizen science projects as the corpus, the effects of the standalone techniques (ethos, pathos, and logos) and mixed-rhetoric techniques of persuasion were examined empirically. The results informed that pathos and logos had significant advantages over ethos. Taking a mixed-rhetoric approach to the endorsement text with a mix of pathos (55%) and logos (45%) maximized the appeal of citizen science projects, and the influence of this approach had an inverted U-shaped effect. On the identity of the endorsers, the professors, students, and amateur researchers shared a similar rhetorical approach, while the industrial researchers shared another. However, from the influence of endorsement rhetorical strategies, the impact of amateur researchers was consistent with that of the industrial researchers (both pathos and logos were positive); and professors (only logos was positive) and students (only pathos was positive) reveal some differences. Finally, endorsement rhetoric strategies exerted a greater influence on the humanities and social science projects than on the natural science projects.