Drawing on Lave and Wenger's (1991) and Wenger's (1998) "communities of practice" (CoP) framework, this study explores the shared repertoire of humor practices in the creation of community within the context of a culturally diverse and multilevel adult Arabic language classroom consisting of two native speakers, five heritage language learners (HLLs), and three second language (L2) learners. These learners were the first cohort of students to participate in a new government-funded university Arabic Flagship Program. Employing both a macro-level ethnographic analysis and a micro-level discourse analysis of video-taped classroom interaction, this study analyzes how participants displayed their individual and "relational" identities (Boxer & Cortes-Conde, 1997), community membership, and levels of participation in this classroom community through conversational joking and responses to canned joke-telling by the teacher. I analyze the data through notions of "frames," "footing," "keying" (Goffman, 1974, 1981; Gumperz, 1982), "double-voicing" (Bakhtin, 1986), and other contextualization cues. I also draw on the findings of previous research on humor in conversation (e.g., Bell, 2002; Boxer & Cortes-Conde, 1997; Norrick, 1993, 2004; Sacks, 1995) and humor in the classroom (e.g., Cekaite & Aronsson, 2004) in interpreting my data. The findings reveal humorous interactive processes and negotiations of meaning which make up the shifting participation of learners in this classroom community. They show patterns of language in interaction by learners, such as teasing classmates by code-switching into other dialects of Arabic which differed from a student's own heritage dialect, teasing the teacher or classmates with Arabic colloquialisms, parodying the teacher's voice, and a hierarchical display of responses and peer scaffolding to canned jokes told by the teacher. I argue that these humor practices were not only sites for identity display and relational identity display by my participants, but they also helped to mitigate tensions, soften face-threatening acts, and protect members' positive face needs in the classroom, ultimately contributing to the creation of a very inclusive, close-knit community with relatively low language learning anxiety for all its members. I also suggest that these humor practices created beneficial contexts for scaffolding and learning of Arabic culture and dialect. The findings are additionally discussed in terms of the CoP framework as well as more recent expansions and critiques of this framework (e.g., Haneda, 2006). [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]