With an increase in technology to mediate learning and a shift to more student-centred approaches, open-ended online assignment tasks are becoming more common in higher education. Open-ended tasks offer opportunities for students to develop their own interpretations of the requirements, and online technologies offer greater flexibility and afford new types of interactions with teachers and other students. This paper presents a study of students' task interpretation and self-set goals in the context of five open-ended online assignment tasks. The findings presented in this paper demonstrate the importance of a high-quality task understanding for goal setting and suggest practical implications for task design and support.