Structure of observed learning outcome
The structure of observed learning outcomes (SOLO) taxonomy is a model that describes levels of increasing complexity in student's understanding of subjects. It was proposed by John B. Biggs and K. Collis and has since gained popularity.
- Pre-structural – The task is not attacked appropriately; the student hasn’t really understood the point and uses too simple a way of going about it.
- Uni-structural – The student's response only focuses on one relevant aspect.
- Multi-structural – The student's response focuses on several relevant aspects but they are treated independently and additively. Assessment of this level is primarily quantitative.
- Relational – The different aspects have become integrated into a coherent whole. This level is what is normally meant by an adequate understanding of some topic.
- Extended abstract – The previous integrated whole may be conceptualised at a higher level of abstraction and generalised to a new topic or area.
- ATHERTON, J. S. (2005) Learning and Teaching: SOLO taxonomy. [On-line] UK: Available:  Accessed: 7 June 2007
- Biggs, J. B. and Collis, K. (1982) Evaluating the Quality of Learning: the SOLO taxonomy. New York, Academic Press
- TEDI. Biggs’ structure of the observed learning outcome (SOLO) taxonomy. 
- Biggs, J. B. (1999). Teaching for quality learning at university. Open University Press