The overall purpose of this study was to explore the dynamics of teaching and learning in the context of an informal, online discussion forum. This investigation utilized the Community of Inquiry (CoI) elements of Teaching Presence and Social Presence along with the construct of Learning Presence to examine Adobe® Forums, Photoshop® for Beginners Forum (PfBF) an internet discussion forum designed to provide support for beginning users of Adobe Photoshop. The researcher collected four days of discussion post data comprising 62 discussion threads for a total of 202 discussion posts. During this initial pilot analysis, the discussion threads were divided into posts created by members who were deemed to be acting as teachers and posts written by members acting as learners. Three analyses were conducted. First, a pilot analysis was conducted where the researcher divided the data in half and coded 31 discussion threads and a total of 142 discussion posts with the Teaching Presence, Social Presence and Learning Presence coding schemes. Second, a reliability analysis was conducted to determine the interrater reliability of the coding schemes. For this analysis two additional coders were recruited, trained and coded a small subsample of data (4 discussion threads for a total of 29 discussion posts) using the same three coding schemes. Third, a final analysis was conducted where the researcher coded and analyzed 134 discussion posts created by 24 teachers using the Teaching Presence coding scheme. At the conclusion of the final analysis, it was determined that eighteen percent (18%) of the data could not be coded using the Teaching Presence coding scheme. However, this data were observed to contain behavioral indicators of Social Presence. Consequently, the Social Presence coding scheme was used to code and analyze the remaining data. The results of this study revealed that forum members who interact on PfBF do indeed exhibit Teaching Presence behaviors. Direct Instruction was the largest category of Teaching Presence behaviors exhibited, over and above Facilitating Discussion and Design and Organization. It was also observed that forum members serving in the role of teachers exhibit behaviors of Social Presence alongside Teaching Presence behaviors.