Pay Attention, Please: Formal Language Improves Attention in Volunteer and Paid Online Experiments

Participant engagement in online studies is key to collecting reliable data, yet achieving it remains an often discussed challenge in the research community. One factor that might impact engagement is the formality of language used to communicate with participants throughout the study. Prior work has found that language formality can convey social cues and power hierarchies, affecting people's responses and actions. We explore how formality influences engagement, measured by attention, dropout, time spent on the study and participant performance, in an online study with 369 participants on Mechanical Turk (paid) and LabintheWild (volunteer). Formal language improves participant attention compared to using casual language in both paid and volunteer conditions, but does not affect dropout, time spent, or participant performance. We suggest using more formal language in studies containing complex tasks where fully reading instructions is especially important. We also highlight trade-offs that different recruitment incentives provide in online experimentation.