For children with developmental or language delays, mand interventions have been identified as an integral part of educational programming (e.g., Greer & Ross, 2008; Shafer, 1994; Sundberg & Michael, 2001). Mands, which are the most elementary forms of verbal behavior, allow individuals to begin to contact social contractual contingencies; thus, making it an important prerequisite in the development of verbal behavior, communication, and social skills. In Study 1, the experimenter conducted a systematic review of mand interventions that target the increase of vocal mands in the literature. The review discusses the specific interventions employed, the general characteristics of the studies reported, and the specific and collateral effects of each intervention. The results and possible future directions were discussed in terms of the current literature. In Study 2 (published as Naresh, Short, & Fienup, 2020), the experimenters examined the effects of the Speaker Immersion Procedure (SIP) on the emission of vocal verbal operants across settings for 3 preschoolers. The procedure involved providing participants with 100 opportunities to mand by either contriving or using naturally occurring establishing operations (EOs) across the school day. Results indicated that the implementation of the SIP led to increases in the emission of target mands in the presence of specific contrived EOs and increases in the emission of vocal verbal operants (i.e., mands and tacts) in non-instructional settings (NIS). Study 3 extended the findings of Study 2 wherein the effects of different levels of the SIP on the emission of vocal verbal operants across settings and the emission of peer observing responses were studied. Using a nonconcurrent multiple probe design, the experimenters provided 6 participants (i.e., 3 dyads) with either 100 or 50 opportunities to mand. The differential effects of each SIP procedure were studied in terms of the number or mands emitted in the presence of specific contrived EOs, the number of vocal verbal operants (i.e., mands, tacts, sequelics, and conversational units) emitted in NIS towards adults and peers, and the number of peer observing responses emitted during free play. [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.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]