In the rush to embrace cognitive science, many a teacher has signalled their enlightenment with a critique of classic education research, most notably the work of US psychologist Benjamin Bloom, best known for his taxonomy, published in 1956. Bloom’s taxonomy is a set of three hierarchical models used to classify educational learning objectives into levels of complexity and specificity.

The three models cover learning objectives in the cognitive, affective and sensory domains. Interestingly, most teachers will probably have seen only the cognitive domain. This comprises of knowledge (broken down into types of knowledge), comprehension, application, analysis, synthesis and evaluation.

The model is often presented as a pyramid. Although the original Bloom publication suggests a hierarchy, some interpretations have gone so far as to argue that knowledge is “lower order” and thus less important, while evaluation, for example, is “higher order” and therefore more important. Certainly, this is a key feature of many critiques from teachers embracing cognitive science.

However, it seems Bloom never intended for the model to be used this way, and putting the mistranslation right took many years.

In 2001, Anderson and Kratwohl finally published a “revised Bloom”, in which they incorporated some of Bloom’s own concerns and criticisms of his original taxonomy (for an overview, see Kratwohl, 2002).

There are several differences in the revised version. Some of the order changed and the cognitive dimension was reworded to use verbs, denoting concrete actions and cognitive processing: remember, understand, apply, analyse, evaluate and create.

Bloom was clearly aware of the difference between knowledge and the mental and intellectual operations performed on, or with, that knowledge. In the revised Bloom, we therefore have a separate knowledge dimension, which makes a distinction between factual knowledge, conceptual knowledge, procedural knowledge and metacognitive knowledge.

In Anderson and Krathwohl’s revision, we can also see how the cognitive dimension is displayed horizontally. Extra care was taken to make sure that elements of the taxonomy were not deemed more or less important: the distinction between them is about the complexity of cognitive processing.

For example, “remember” would likely require less cognitive processing complexity than “analyse”. But note that, even here, such boundaries are fluid. The main message, in my opinion, is that all processes in the cognitive dimension are important.

So, when the critiques of Bloom come out, are they talking about the original from 1956 or the 2001 version? Or, as I have seen, are the two often mixed together? There are so many misrepresentations of the work that much of the criticism is inaccurate.

Despite this, those criticisms have led many to dismiss Bloom’s taxonomy altogether. I think that would be a shame: it might well be an ideal taxonomy for any pedagogical inclination.

And interestingly, the complexity of cognitive processing and the role of different types of knowledge that Bloom describes fit nicely with the advent of cognitive science. Ironically, those most keen on that field should be its biggest cheerleaders.

Dr Christian Bokhove is a lecturer in maths education at the University of Southampton and a specialist in research methodologies

This article originally appeared in the 25 October 2019 issue under the headline “Bloom or bust: why every teacher should understand his taxonomy”