Study instruments

For Phase 1, a qualitative instrument was created and pilot-tested with two adolescents and two young-adult interns and then revised for completion. The instrument consisted of 41 open-ended questions that asked participants about (1) their current knowledge about tobacco product content (2) the perceived harm of tobacco use, (3) social exposure to tobacco use, and (4) ways to improve the initial library of text messages. Phase 1 aimed to support the design of the text messages by using adolescents’ conversational styles during the qualitative sessions. Following the qualitative session, participants completed a survey on their demographic characteristics, tobacco use status (i.e., cigarettes, cigars, hookah, and vaping), and susceptibility to use tobacco [29]. For Phase 2, the ideation sessions instrument included an online cloud-based table that was accessed by all the attendees of the session at the same time, allowing them to go over the initial version of the messages and improve these messages on the editable table. Details of the instruments for Phases 1 and 2 can be found under the S1 File.