The term 'engagement' is much researched but tricky to define in the field of educational technology and online learning. In this short paper I will offer three perspectives on what 'engagement' means in online learning environments and provide some advice to educators on how student engagement in online learning might be promoted. The presentation of three perspectives is in no way meant to represent the entire literature base in the area. But the three perspectives hopefully provide a useful framing of how academic staff -- particularly those new to online teaching and learning -- can approach the concept of student engagement in online learning.