This pilot study introduces a scale to assess structural knowledge in concept maps. The need to increase our understanding of structural knowledge through improved assessment is made evident in a review of research that indicates that its quality is related to problem-solving abilities. The new scale is derived from Biggs and Collis' (1982) Structure of the Learning Outcome (SOLO) taxonomy and Rumelhart and Norman's (1978) modes of learning (structuring, accretion, and tuning). It is applied to link descriptions in an enhanced concept map structure that has been dubbed the "concept map+." Eight levels of link quality can be recognized with the new scale. This builds on the original concept map assessment scale of Novak and Gowin (1984) where just three types of link quality were acknowledged.