This study examines influence of online text-based discussions for secondary school students. It aims to analyze students' shares and views with the goal of exploring the implications of online synchronous text-based discussions held in the Information Technology and Software lessons. It was carried out as a case study in which 10 discussion sessions were held involving 26 students enrolled in a state secondary school. The case study was chosen because it makes it possible to examine a situation in detail and in depth. The findings were discussed in relation with the "Community of Inquiry" (CoI). It was found that with online synchronous text-based discussions, the students experienced building of meaning or collaboratively verified mutual understanding in line with the predetermined objectives. Online text-based discussions helped achieve a meaningful learning experience through development of social, cognitive and teaching presence. Student-student interactions in formal educational environments facilitated the formation of social presence in the online learning environment. Peer reviews concerning the discussion topics, shared contents and the teacher feedback contributed to the development of the students' views on the subject. Off-topic or irrelevant shares in the discussion sessions might cause a negative impact on the students.