An examination of the perceptions of mLearning held by secondary teachers as well as mLearning best practices and professional development. Using the SAMR model (Puentedura, 2013) along with Romrell's (2014) definition of mLearning, this study evaluated mLearning activities (tools and applications) currently being used by secondary school teachers. The mLearning activities were also evaluated and measured against the SAMR model to determine their level of technology integration (substitution, augmentation, modification, and redefinition). This study also identified the challenges and obstacles standing in the way of creating these types of transformative mLearning activities. Four research questions guided this study. This study was an explanatory mixed methods study and the data was obtained from the online surveys and one-on-one interviews of secondary school teachers that have integrated mLearning (mobile learning) into their teaching. The 103 respondents came from 23 states across America as well as one respondent from Mexico. Six of the survey respondents were purposely selected for a one-on-one phone interview, the purpose of the interview was to clarify and expand upon the data collected from the survey responses. The data obtained was analyzed and the findings suggest that while most school districts are integrating various types of technology, mLearning best practices are not being presented, supported and developed in the districts' professional development. Furthermore, most districts are not supporting the use of technology integration models such as the SAMR model. The findings show that the respondents created mLearning activities most often at the Enhancement levels (Substitution and Augmentation) as opposed to the Transformational levels (Modification and Redefinition). The biggest challenges hindering the creation of Transformational mLearning activities were the lack of training and not enough time. Recommendations were made to shift focus from promoting technology tools and usage to supporting teachers in designing mLearning activities (personalized, situated, and connected using a mobile device) that support a transformation of learning and the development of 21st century skills. [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.]