Creating an online learning environment that engages learners beyond the given course period is challenging. Open, participant-driven discussion forums, where participants are provided with greater agency on what to learn, how to learn, and whom to learn with, have a unique potential to help learners engage in learning experiences based on their interests and needs. Based on sequential and qualitative analysis of speech acts found in the participant-initiated discussion threads hosted as part of a massive open online course, this paper explored the impact of participant actions as facilitative moves to gain a better understanding of the types of actions in the discussion that stimulated deeper engagement with the ideas of interest. The analysis identified several facilitative moves that nurture or hinder deeper conversation in an open online discussion forum that has design implications. The paper also highlights the potential of analysing conversation sequences of posts as a promising method to study discussion forum data.