This study investigated the potentials of face –to- face and computer mediated conversation (CMC) as two speaking modalities on students’ engagement. To this end, 30 Iranian male intermediate EFL learners were selected on the basis of their performance on OPT (Oxford Placement Test) and assigned into the research groups. The progression of face- to- face and CMC groups from limited to elaborate engagement at verbal, paralinguistic and functional levels was assessed using transcription analysis in face-to-face group and chat log analysis in CMC group. The limited and elaborate student engagement indicators in two modalities were identified via Maxqda software. The results of Maxqda analysis indicated that limited engagement was associated with appeal for help, silence, pauses and hesitations, focus on syntax, involvement with procedural talk and L1 use. Respectively, elaborate engagement was associated with avoiding L1 use, focus on discourse, involvement with actual talk and strategic discourse management rather than pause and silence. Chi-square analysis on frequency of indicators of limited and elaborate engagements on verbal, paralinguistic and functional levels indicated that limited and elaborate engagements occurred with different proportions in face-to-face and CMC conversations. Teaching practitioners would benefit the findings of the study since the findings illustrate how students’ engagement in learning evolves and how speaking modalities may impact the pattern of students’ engagement over time. The finding also suggest one way for improving student engagement without over-intervening of teachers is using modalities such as forums where the teacher presence is limited and students have to manage the discourse themselves which in turn increases student engagement.

这项研究调查了面对面和计算机介导的谈话（CMC）作为学生参与的两种说话方式的潜力。为此，根据他们在OPT（牛津分班考试）上的表现，选择了30名伊朗男性中级英语学习者，并将其分配到研究组中。使用面对面组的转录分析和CMC组的聊天记录分析评估了面对面组和CMC组在言语，副语言和功能水平上从有限到精心参与的进展。通过Maxqda软件确定了两种模式中有限且精心设计的学生参与度指标。Maxqda分析的结果表明，参与度有限与寻求帮助，保持沉默，停顿和犹豫，专注于语法，参与程序性讨论和使用L1。分别地，精心的参与与避免使用L1，专注于话语，参与实际谈话和战略性话语管理有关，而不是停顿和沉默。在言语，副语言和功能层面对有限和精心参与的指标频率进行卡方分析表明，有限和精心参与的面对面和CMC对话发生的比例不同。由于研究结果说明了学生的学习参与度如何演变以及口头表达方式可能会随着时间的推移影响学生的参与方式，因此，教学从业人员将从研究中受益。