In highlighting the importance of problem-based learning in the development of 21st century skills, (Yun Jo) An (2013) identified the challenges faced by novice teachers in its implementation and suggested strategies to support them. This commentary explores two aspects mentioned in the article, assessment and the role of collaboration, and argues that they need greater critical consideration if the implementation of problem-based learning is to be effective. The role digital technologies can play is discussed and some implications for teacher education are considered.