In many U.S. states, there is a growing population of academically, culturally, and linguistically diverse English learners enrolling in the public educational system. It is important that collaboration occurs between content area teachers and ESL specialists at the secondary level for supporting and equipping teachers with the skills that they need to effectively meet the needs of these students. The problem addressed in this study was that even though collaboration between ESL specialists and content area teachers has been shown to be important, it does not always (or often) occur at the secondary level. Therefore, the purpose of this basic descriptive qualitative study was to investigate why collaboration did not typically exist between content area teachers and ESL specialists at the secondary level at a large urban high school in Indiana and to also understand the lived experiences of teachers in the processes of collaboration where it did occur. The researcher framed the topic of teacher collaboration through the use of social cognitive theory and endeavored to discover how the teachers' pedagogical approach in regards to collaboration was developed through the connections of their daily lived experiences and their perceived generalizable abstractions about collaboration. The following three research questions were used to guide this study: RQ1: What do content area teachers perceive to be the main factors behind successful collaboration or the lack of collaboration between themselves and ESL specialists at the secondary level? RQ2: What do ESL specialists perceive to be the main factors behind successful collaboration or the lack of collaboration between themselves and content area teachers at the secondary level? RQ3: How are teachers' perceptions of the factors behind successful collaboration or the lack of collaboration between ESL specialists and content area teachers related to the processes of collaboration? The gathering of data consisted of surveys and interviews with two ESL specialists and six content area teachers. In order to understand how the interview data sets related to the research questions, a thematic analysis was employed. Through data analysis, the researcher determined that the participants' pedagogical approach to collaboration was affected by the ability to connect lived experiences with generalizable abstractions in some areas, while not being able to connect their generalizable abstractions to their lived experiences in other areas. The researcher also determined that there were several factors that the participants perceived to lead to successful collaboration or the lack of collaboration between ESL specialists and content area teachers that were related to the processes of collaboration. The results of the researcher's findings of this study indicate that for the content area teachers and ESL specialists at this particular site to have successful collaborative processes, it would be necessary for several additional factors to be employed. Most notably were formalized opportunities for collaboration, knowledge of fellow faculty members and their roles, and a sense of the importance of the collaboration through administrative support. [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.]