Bloom’s TaxonomyPosted: March 23, 2016
Bloom’s taxonomy was developed in the early 1950s by a committee led by the educational psychologist, Benjamin Bloom. The cognitive domain of this taxonomy – which is usually what people mean when they refer to “Bloom’s taxonomy” – is ubiquitous in education and is probably one of the few concepts that most teachers have heard about. It was revised in 2000 and the original and revised versions have a slightly different emphasis, with nouns having turned into verbs and an equalisation of the top three layers:
The taxonomy is a method for classifying educational objectives. Does it fit with what we know about research? Well, perhaps this question is moot. The only way that we could base a classification of learning objectives on anything scientific is if we had firm evidence that there were different brain processes involved. We certainly did not have such evidence in 1956 and we don’t have much now. However, I don’t think Bloom and his committee made or implied such a claim.
There are aspects that I like about the taxonomy. One way of reading the hierarchy is to suggest that we clearly need to know something before we can progress to applying it and so on. However, there are other forms of exegesis that are deeply troubling.
Higher order thinking skills
The top end of Bloom’s taxonomy – the parts that I’ve coloured yellow – are often known as ‘higher order thinking skills’. Again, the ‘higher order’ part is just another classification and, as such, is pretty neutral, although I would disagree with the idea of calling these objectives ‘skills’ and I will explain why later.
The main problem arises when educators start to infer that these are superior kinds of objectives. This can lead to the suggestion that these objectives should be emphasised over the ‘lower order’ objectives of merely remembering rote, disconnected facts. Most teachers who have worked in schools over the last 20 years have probably been exposed to some kind of process where observers come and look at classrooms and then pronounce that not enough higher order questions are being asked or tasks set.
I don’t think that this is what the authors of the taxonomy would have wanted. I think the intention is to emphasise the crucial, foundational importance of knowledge; knowledge first and then everything else. But this doesn’t seem to be how it is interpreted in the wild. As Karen Tankersley suggests in this extract from her book on higher order thinking, “There is simply too much information in the world for us to waste students’ time with regurgitations of basic facts.”
The conjuring into being of a class of thing
The other major problem with Bloom’s taxonomy is that it encourages us to imagine that there is a stable thing that we can label ‘analysis’, ‘evaluation’ or whatever. We assume that ‘analysis’ involves a certain set of mental processes and that, by practising analysis, we may become better at analysis. The trouble is that it’s not at all clear that the mental processes involved in analysing a bar chart have anything in common with those involved in analysing a TV commercial. The domains are completely different. To become proficient at analysing bar charts we must first learn about bar charts before seeing different examples and different contexts. After practice, we may reach our objective. However, once we move on to TV commercials we must start again from the bottom of the hierarchy.
This, at least, is what the research tends to show: First you need a solid base of knowledge. Analysis, evaluation or creativity are not skills that can be trained or exercised like a muscle and then applied flexibly, as required. If we think that they are then we might miss out the vital steps of teaching the domain knowledge that true expertise requires.
I think it is time to put Bloom’s taxonomy out to pasture. I know less about other generic learning taxonomies such as SOLO but they do, superficially at least, seem to suffer from the same issues of interpretation. Instead, we should invest our efforts in attempting to sketch-out out the pathways of progress that are followed in developing an understanding of specific concepts. These would be of real, practical value to teachers, and far more use than a set of cliches to be trotted-out at the next whole-staff meeting.
Update: @penpln has sent me a link to this paper that well worth reading.