SOLO Taxonomy

Topic Progress:

Given that the process of learning is linked so strongly to the outcomes that are attained, we can gain insights into the students’ process, or approach, by examining the outcome of their work.

Biggs and Collis1, developed the idea of the SOLO taxonomy, which can be used to evaluate the quality of a student’s work. SOLO (Structure of the Observed Learning Outcome) can be used to both assess learning and to design learning outcomes.

SOLO Taxonomy


As you can see from the image above, there are five levels of quality identified in the taxonomy.

  1. Prestructural
    Responses at the prestructural level reflect incompetence and indicate the the student has completely missed the point.
  2. Unistructural
    These responses indicate the the student can identify one relevant aspect of the idea, but what they identify is an isolated factoid unrelated to any other ideas.
  3. Multistructural
    Multistructural responses indicate that the student can identify more than one relevant aspect of the idea, but the content of their response is still characterized by factoids unrelated to each other.
  4. Relational
    Relational responses are more complex than previous levels and indicate that the student has not only identified several relevant aspects, but is able to relate those aspects into a coherent model.
  5. Extended Abstract
    The highest level of understanding represented in the taxonomy, indicated by extended abstract responses, are characterized by relational responses that are not only internally coherent, but are coherent when applied to different situations.

The video below explains the SOLO taxonomy in more detail.


  1. Biggs, J., & Collis, K. (1982). Evaluating the quality of learning: The SOLO taxonomy. New York: Academic Press.