<![CDATA[This study examines the influence of argument quality and source credibility in WhatsApp group messages on members' attitudes toward participating in running events, while testing focused immersion as a moderating variable. The study is grounded in the Elaboration Likelihood Model, which explains attitude formation through central and peripheral routes of message processing. A quantitative explanatory survey was conducted among 90 members of the Fakerunners Bandung running community, selected from 864 WhatsApp group members through simple random sampling. Data were collected using an online questionnaire and analyzed using Pearson correlation, multiple linear regression, and Moderated Regression Analysis. The findings show that argument quality has a significant positive effect on members' attitudes, and source credibility also has a significant positive effect. Focused immersion has a significant direct effect on attitudes, indicating that members who are more absorbed and attentive when reading running-event information tend to hold more positive attitudes toward event participation. However, focused immersion does not significantly moderate the effect of argument quality or source credibility on attitudes. The results suggest that WhatsApp group persuasion in running communities is shaped more by the direct strength of message content, credible senders, and members' attentive engagement than by the interaction between focused immersion and persuasive message cues. Keywords: argument quality; source credibility; focused immersion; WhatsApp group; running community]]>
