Thinking about Learning: The SOLO Taxonomy

What is the SOLO Taxonomy?

Over the last six or seven years, I have spoken to a number of people about the SOLO Taxonomy and one of the most common responses is ‘I’ve heard of Bloom’s Taxonomy….’

Like Bloom’s taxonomy, it is a hierarchical way of structuring the language around learning. This blog will explore the similarities and differences as well as how useful these are for teachers.

A brief history of the SOLO Taxonomy

Developed in the early 1980’s by Biggs & Collis in Australia, these researchers looking at trying to describe a hierarchical sequence of ‘learning’ among undergraduate students. They classified learning using 5 stages (with a brief description of what each stage means)

  • Pre-structural (not really knowing anything)
  • Uni-structural (knowing one relevant thing)
  • Multi-structural (knowing several relevant things)
  • Relational (connecting several relevant things in a meaningful way)
  • Extended abstract (applying this learning successfully in a new context)

Others including Pam Hook and Julia Mills in New Zealand took the ideas within the taxonomy and looked to apply these to other age groups.

In the UK, it was being discussed at the very end of the National Strategies as an idea with some promise and has been reviewed as part of the Beyond Levels report, published in 2014 (along with other forms of assessment, including Bloom’s Taxonomy).

A short history of Bloom’s Taxonomy

Many teachers would be familiar with Blooms’s taxonomy as the following hierarchy:

  • Knowledge
  • Comprehension
  • Application
  • Analysis
  • Synthesis
  • Evaluation

As a common component of many teacher training programmes, Bloom’s taxonomy is often shared with teachers by teacher educators.

Developed in the late 1940s and early 1950s, the publication of the ‘Taxonomy of Educational Objectives’ was designed to improve communication between educators. The intent was to help them have a common understanding and language as they designed curricula and examinations.

It became known as ‘Bloom’s’ Taxonomy, named after the lead of the group, which was a much snappier name..

Less commonly known is that the Bloom’s Taxonomy has three domains (or areas) that it covers.

These are:

  • Cognitive (Knowledge and thinking based domain)
  • Affective (Emotion and feeling-based domain)
  • Psycho-motor (Manipulation and action-based domain)

Teachers and educators are typically made aware of the first area (cognitive), but the others are often omitted.

Also less commonly known is that there was a revision to the taxonomy, led by Anderson and Krathwohl (who was part of the original group involved in the construction of the ‘Bloom’s’ Taxonomy. The revised Bloom’s taxonomy (also known as Anderson’s Taxonomy) made some modifications to the order of terms. In particular, the last two terms ‘flipped’, with ‘Create’ (replacing the term synthesis) now the top of the hierarchy, overtaking evaluation.

SOLO vs Bloom’s Taxonomy

Bloom’s has a distinct advantage from a teacher’s point of view in feeling more intuitive as the terms used are more familiar, using everyday language to describe them. The terms in SOLO seem much more complex and require translating in order for them to make sense. Pam Hook has a number of resources using SOLO and one video in particular where primary age pupils are discussing their learning using the terms. Others, for example David Didau who at first advocated its use, then changed his mind (as read in his blog) suggesting that the language of the taxonomy was over-complex and there were simpler ways of doing things.

The difficulty that many pupils have with Bloom’s is that while the language may feel intuitive to teachers, it doesn’t necessarily feel that way to pupils as they are quite abstract. If they have well developed thinking, they would find the terms straightforward as they would understand what analysing was and how it was different to explaining. This can lead to frustration on the part of the teacher as they use the terms expecting pupils to understand them in the same way.

Having used SOLO in a number of different ways over the last 6 or 7 years, I feel that language aside, it has something very positive going for it. The concept behind ‘relational’ thinking is ‘linking ideas together’. I have found this to be a very pupil friendly way of getting across the ideas of ‘explaining’ (linking ideas together in a way that answers a question) or comparing ‘linking ideas by looking at the similarities and differences’. Pupils get the hang of linking quickly, particularly if used with the hexagons (although there are some things in this video that perhaps would be worthy of its own blog!)

We have included the thinking behind SOLO in one of our interventions ‘Deeper Thinking‘ which has recently undergone a pilot funded by the EEF and Wellcome Trust.

Crucially, if you think about the whole of Bloom’s taxonomy, particularly the revised version has more areas of agreement with the SOLO taxonomy. Maybe they aren’t so different after all.


Biggs, J.; Collis, K. (1982). Evaluating the quality of learning: the SOLO taxonomy (structure of the observed learning outcome). Educational psychology series. New York: Academic Press.

Bloom, B.; Engelhart, M.; Furst, E.; Hill, W.; Krathwohl, D. (1956). Taxonomy of educational objectives: The classification of educational goals. Handbook I: Cognitive domain. New York: David McKay Company.

Anderson, Lorin W.; Krathwohl, D., eds. (2001). A taxonomy for learning, teaching, and assessing: A revision of Bloom’s taxonomy of educational objectives. New York: Longman.

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