On Thursday, Sept. 24, Celina Su, an internationally recognized expert in critical participatory action research, urban studies, and grassroots organizing, will deliver "Participation for What?," a keynote speech on the possibilities and tensions in community-based initiatives. Her presentation will begin at 4 p.m. in Old Main Chapel. On Friday, Sept. 25, the conversation continues with a community panel at 9 a.m. and two interactive workshops at 10:30 a.m.; both will be held in the Kittredge Multipurpose Room.