Introduction: This research is based on experiences by international students. In Teaching for sustainability (15 credits), the perspective is learner oriented with a holistic approach on education and sustainability. The heterogeneous group of students has a variety of knowledge on sustainability issues, different experiences of learning activities and examination forms. Consequently, a common platform for progression of knowledge formation among the students is needed. One learning activity is to read World on the Edge (Brown, 2011), formulate three questions on environmental and sustainability challenges that the student considers important. One question per student is selected by the lecturer and the student directs the discussion among 5-7 students. The students share their thoughts and knowledge for meaning-making, discussions through the seminar. The learning outcome is to be able to describe what effect humans have upon their environment. Objectives: The aim of the study is to investigate how heterogeneous groups of teacher students experience a student-driven, non-traditional learning assessment, their learning process and meaning-making within environmental and sustainability education. Methods: Qualitative group interviews, semi-structural questions, and analysis were carried out through a phenomenographic approach. Focus was on previous experiences of assessments, ways of reading the book and formulating questions, expectations and reflections, and learning processes for meaning-making. The interviews with the international teacher students (n=41) in 2012 and 2014 were recorded, transcribed and thematically categorised. Results: To many students the assessment was a new learning experience. While reading the book students were mainly concentrating on bigger concepts. A few students were afraid as they were unfamiliar with planning and taking responsibility for a discussion. However, the participatory and collaborative learning assessment with sharing of experiences among the students resulted in a rewarding meaning-making process. After the assessment students continued to reflect and talk about the questions raised. According to them, it generated a deep learning opportunity compared to written examination. A tentative result shows some categories of the students’ experiences of meaning-making: developing critical thinking, focusing on learning and understanding, learning by collaboration, seeing a bigger picture, and taking responsibility in learning for understanding. Conclusion: Besides assessing a learning outcome, the learning needs are identified through the learning activity to be promoted for continued learning in the course. When students share their knowledge and experiences of global environmental and sustainability challenges, sustainability literacy for understanding seems to develop. The students describe their learning processes as on-going after closing the seminar.