The topic of praise and more specifically, behavior-specific praise, in special education is complex. It requires an investigation of multiple types of praise in a variety of settings and a variety of individuals with even more severe intellectual and developmental disabilities and other impairments (IDDI). Historically, in much research, investigation of praise effectiveness concentrated on strictly mild disabilities, limited settings, or simply assumed that praise is an effective strategy. The purpose of this meta-analysis was to synthesize the experimental design studies published between 2008 and 2024 examining the effectiveness of praise on skill acquisition among individuals with IDDI. The results of 20 studies meeting inclusion criteria resulted in the analysis of 24 experiments with a total of 80 participants with a variety of single-subject experimental designs. The methodology of design-comparable standardized mean difference was used to estimate the effect size of praise on skill acquisition. While practitioners should create a positive learning environment, the results of this study indicate that there is only limited evidence to support praise as an effective universal strategy to teach skills to individuals with IDDI. Further, the analysis of contemporary research indicates limited variety in participants' ages, diagnoses, and environments, which is concerning given the focus of special education on preparation for transition to adulthood outside of school or clinical settings. Furthermore, there is no research on this topic among adults with IDDI and there is no research on the use of self-praise, or praise outside of educational or clinical settings. Overall results indicate that praise is somehow effective compared to no-praise but is ineffective compared to other low-effort high-effectiveness reinforcers. This meta-analysis also revealed that, following assessments of the preferences of individual participants in the majority of included studies, other reinforcers may be more effective in fast skill acquisition. As an implication for practitioners, praise should not be used as a default reinforcer. Practitioners should not assume that praise is a low-effort, high-effectiveness strategy because current research does not support that. Instead, practitioners should examine students' preferences for a variety of low-effort tools (high-fives, tokens, fidget toys) and use these as highly effective reinforcers, especially if praise is not reinforcing enough. More research is needed to give practitioners, parents, special educators, and administrators effective strategies to teach our individuals with IDD skills they need for the most independent and fulfilling lives. [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.]