The effectiveness of different types of practices for promoting practitioner and parent adoption of different kinds of assistive technology and adaptations with young children birth to 105 months of age was the focus of a meta-analysis. Six operationally defined adult learning method characteristics and between 2 and 5 practices for each characteristic were used to code and analyze the results for both adult (practitioner and parent) and child outcomes. The synthesis included 35 studies with 839 adult participants and 1100 child participants. The assistive technology that were the focus of training included speech generative devices (e.g., CheapTalk), computers (e.g., adapted keyboards), and switch activated devices and toys. Results showed that certain practices for each adult learning method characteristic proved most effect in terms of changes and improvements in both adult and child outcomes. These included trainer description and explanation of the assistive technology for introducing the devices to the trainees, learner-informed experiences and trainer demonstration of the devices for illustrating how to use the devices, trainee use of the assistive technology and trainer-guided trainee practice using the devices, trainer feedback on the trainees use of the assistive technology, and trainee standards-based self-assessment of their knowledge and skills and the provision of opportunities to generalize the use of the assistive technology for assessing mastery. Results also showed that when more of the most effective practices were used as part of the training, the greater the adult and child outcomes; and the greater positive benefits when the child(ren) who were to use the assistive technology were present during the trainings. Implications for promoting practitioner and parent adoption and use of assistive technology and adaptations are described. The following are appended: (1) Characteristics of the Adult Study Participants; (2) Characteristics of Child Study Participants; (3) Selected Characteristics of Training Studies; (4) Types of Adaptations, Technologies, Adaptive Technologies, and Instruction; (5) Adult Learning Method Practices Used to Promote Use of the Assistive Technology and Adaptations; (6) Adult Participant Outcome Measures and Cohen's d Effect Sizes; (7) Child Participant Outcome Measures and Cohen's d Effect Sizes; and (8) Checklist for Promoting the Use of Assistive Technology or Adaptations.