In this commentary, Mary James highlights two problems she deemed critical during her work exploring the relationships between assessment and learning in theory and practice. First, efforts to improve assessment for learning were not always successful either in improving performance or in other ways. Second, and this may be a reason for the first difficulty, it became increasingly clear that the concepts of "assessment" and "learning," and the nature of their relationships, were ill-defined and not well understood. The majority of this article focuses on the second issue because it is foundational and it underpins Baird et al.'s (2017) review article in this issue. However, James adopts a somewhat different perspective on their theme by viewing the relationships between assessment and learning primarily from her interest and experience as an educator. [This article is a commentary on Jo-Anne Baird, et al.'s "Assessment and Learning: Fields Apart" (EJ1149539).]