Bloom’s Taxonomy: More Subtle Than I Thought


Bloom’s Taxonomy.  I can’t remember the first time I heard this famous phrase, but it was surely no more than a few feet inside the door of my first graduate school education class.  Bloom – Benjamin Bloom, the iconic University of Chicago researcher – published his famous taxonomy of educational goals back in 1956 and few educational materials have cast such a large shadow.  I can’t tell you how many times I’ve heard a presenter refer to it as gospel, or all the times I’ve been handed some brightly colored, pyramidal visual graphic of it, or even that ubiquitous spinning wheel thing with all the verbs on it.  I’m sure I’ve got six or seven kicking around in the bottom of my desk. 

It’s not surprising, then, that I’ve come to believe over the past few years that Bloom’s taxonomy represents another one of those invisible boxes that I’ve been operating inside, without realizing it – some useful but ultimately unexamined confine.  I began to have this feeling that for anyone thoughtful about designing educational experiences, the taxonomy is sort of the water we don’t know we’re wet in.

So I figured that the best way to free myself was to go back to the source and read the actual book.  Yes, before the taxonomy was a colorful pyramid, it was actually a *book*!  That way perhaps I could better understand just where Bloom was coming from.  

It wasn’t as easy as it should have been.  In truth, the original book – once I got my hands on it – isn’t particularly long or especially tough to read (especially for someone who is fluent even in “John Dewey”).  Yet because I’m the parent of an infant, it has taken me longer than usual to read much of anything these last five months (or write anything – hence the lack of posts).  Sometimes even puzzling my way through a shopping list feels like it’s beyond me, and there have been several times that I’ve wanted to quietly approach some non-judgmental-and/or-stoned-looking teenaged checkout clerk to help me decipher all of the strange shapes on my shopping list (“B-E-E-R”) that my sleep-deprived brain just can’t make sense of.  

I had always wanted to actually read the taxonomy, so, slowly – and with greater-than-usual difficulty – I finally did.


A few words beforehand about the taxonomy.  

First, as I alluded to before, it’s wildly popular, and it has been since its publication.  And that’s not just among scholars, but among practitioners, as well.  It’s immensely influential in classrooms across the country.  But here is one of the most persistent issues with it: The taxonomy has often been interpreted (unfairly, as you will see) as hierarchical: separating out “lower-order” thinking skills (such as mere remembering) from “higher-order” thinking skills (such as evaluation or synthesis).  This in turn has served, in the eyes of some educators, to devalue the critical ed objectives that require knowledge of specific facts and content.

Despite how well I knew of it, there were also a few key facts about the taxonomy that I didn’t know until I started reading it.  The first is that Benjamin Bloom was not the sole author and creator.  In fact, he was merely the editor, who oversaw the work of an entire committee of many educators and researchers who created the taxonomy.  It’s Bloom’s, certainly, but it’s also many others’.

Also, the taxonomy itself is really only the first version of three.  The first one, the one that everyone knows, is Book 1: The Cognitive Domain.  But there are two others – Book 2: The Affective Domain (which was published later), and Book 3:  The Psycho-Motor Domain.  The cognitive one is far and away the most famous, however – which surely says something important and meaningful about the thrust of our usual educational goals.


The first thing I noticed on reading the taxonomy is that the widely-perceived divide between higher-order and lower-order thinking skills simply doesn’t exist in the book that Bloom wrote.  Yes, he does divide the book into two segments: the goal of “knowledge” (which comprises the first layer of the taxonomy, first, and “skills and abilities” (which make up the next layers), second.  Yet he does not seem to denigrate “knowledge” as mere rote memorization – the way that many devotees of the taxonomy would have it.  Instead, Bloom spends a good bit of time discussing the importance of knowledge as a goal.  And he specifically makes the E.D. Hirsch-ian point that knowledge is fundamental to all of the other educational ends in the taxonomy.  He writes: 

“Problem solving or thinking cannot be carried on in a vacuum, but must be based upon knowledge of some of the ‘realities’ . . . Knowledge becomes either the material with which the problem solving deals or it becomes the test of the adequacy of the problem solving” (33).  

Even in rapidly changing fields, knowledge is taught not so much the understanding that it will be “eternally true,” but as a means for “attacking the problems” of the field, according to Bloom.  

And so, even if the other levels of the taxonomy are considered more cognitively sophisticated, they also *depend* largely on the widest, bottom-most layer of knowledge.  As Bloom writes, “knowledge is involved in the more complex major categories of the taxonomy.”

Even more interestingly, very early in the book, Bloom raises a concern that the committee had in developing the taxonomy: that teachers would perceive it to be a hierarchical ordering, and would only select those objectives considered the most sophisticated.  He writes of the concern that the taxonomy might “tend to abort the thinking and planning of teachers with regard to curriculum, particularly if teachers merely selected what they believed to be desirable objectives from the list provided in the taxonomy” (5).  Instead, Bloom believes the taxonomy will be valuable as a companion, a distillation – but no replacement for the need for teachers to think through educational goals on their own.

Again, I was surprised by the extent to which Bloom broke down all of the knowledge-based educational goals into smaller parts.  Knowledge, Bloom describes, is defined as “those behaviors and test situations which emphasize the remembering, either by recognition or recall, of ideas, material, or phenomena” (62).  Within this discipline Bloom classifies increasingly sophisticated kinds of recall which a student may be expected to undertake – roughly moving from knowledge of discreet specifics, to comprehensive knowledge of “theories and structures.”

I guess that I am one of those educators who has largely imbibed the bias against lower-level educational objectives – i.e., knowledge – because I found myself wondering at first why Bloom spent so much time elucidating so many different aspects of knowledge.  Sure, there’s quite a difference between asking a student to recall the capital of Connecticut and asking a student to name the major schools of educational philosophy and to recite their tenets.  But isn’t that all just a more sophisticated form of memory?  After all, one can train a child to repeat the words “Pragmatism” and “Perennialism,” right?

I felt the same way every time Bloom spent page after page giving complex examples of test questions to illustrate each classification level that he is talking about.  I found myself skipping over these.  “They’re just standardized test questions,” I found myself thinking.  “Who really uses those anymore except test companies?” Any test question worth its salt must be a so-called “performance task” – a complex operation requiring some sort of response from students more than just circling a correct answer.  I found that interesting about my own response to Bloom – no matter who different in complexity Bloom’s sample test questions were, my own bias against multiple choice questions made me see all of his range as similarly basic.  

And yet, it’s fascinating to read this book because it reminds us that times change.  Bloom’s book seems aimed at a time when knowledge was the only sort of goal taught or tested.  One gets the sense from his writing that Bloom created the taxonomy, in part, as a nudge away from the mere rote learning and assessment of rote learning that was popular in the mid-20th century.  He writes, “Many teachers and educators prize knowledge to some extent because of the simplicity with which it can be taught or learned . . .  Because of the simplicity of teaching and evaluating knowledge, it is frequently emphasized as an educational objective out of all proportion to its usefulness or its relevance . . .” (34). It’s as though Bloom does see his aim at classifying all the varieties of knowledge-based educational goals – and he includes so many types because so many teachers assess basic knowledge so often, for such a wide variety of purposes.  So Bloom is really just reflecting existing practice, and attempting to at least clarify it, if not encourage it to grow.

But above all, even though I initially recoiled from so much focus on mere remembering, when I really took the time to read Bloom’s distinctions among various types of knowledge, I found them really useful.  Specifically, Bloom really is focused on connecting memorization and basic knowledge to a wider understanding of what we’re teaching.  Especially useful is his framing of disciplinary knowledge.  Bloom’s taxonomy, when you actually read it – far from encouraging one to abandon all assessing or teaching for “lower level” knowledge – actually encourages a much more capacious sense of the role of knowledge – as “disciplinary knowledge.” The vision that emerges in Bloom is a much more integrated understanding of the facts or terms that we’re teaching in English Language Arts, for instance.  We’re not just teaching them idle terms, he reminds us; we’re teaching students conventions, generic terms, terminology from the field of writing – all of which are necessary for “attacking the problems” (as he would say) in our field.

In a sense, as I step back from the book, I think about two specific types of knowledge in English Language Arts.  

First there is the disciplinary knowledge necessary to pursue problems in the discipline.  This is disciplinary knowledge about how to write, for instance.  Examples might include:

Knowledge about conventions: 

  • Of the English language (an example Bloom cites specifically)
  • Of formal versus informal writing

Then there is knowledge of genres:

  • Analytic essay:  The components of structure (thesis, topic sentence, quote analysis sentence, etc.).  
  • Persuasive essay:  The point and counterpoint
  • Creative essay:  The plot techniques one might use (conflict, resolution, climax, antagonist).  

Many of these are disciplinary terms that not only aid in creation, but in talking about and discussing how to improve one’s work – in attacking the “problem” of how to write well.

Knowledge of criteria:

  • This is, writes Bloom, “knowledge of . . . criteria for judgment appropriate to the type of work and the purpose for which it is read.” This would include the standards by which a college essay is judged: Does it sell a candidate along particular lines, for a particular audience of admissions counselors?

Knowledge of methodology:

  • This is what Bloom calls “knowledge of the methods of inquiry, techniques and procedures employed.” This is the knowledge of how to attack writing – the process-based knowledge.  Much like the scientific process does, this shows students how to attack the problems they face, in a process fashion.  This might include: knowledge of how to complete an outline, what the different drafts in a multi-draft process are called, and how they work.  These are ideas and even techniques that have worked well for writers in the past to attack the problem of the discipline – i.e., getting words down onto a page.

From here, Bloom moves from knowledge to the domain of what he calls intellectual skills and abilities.

First is comprehension, which means, for Bloom, the notion of a basic understanding of some shared communication – whether written (a book or article), observed (a chemistry lesson), or heard (a lecture).  Bloom divides comprehension into three different smaller levels: translation (which essentially means being able to restate a problem in your own words); interpretation, which requires being able to “reorder” the ideas in the mind of the individual (as in inferences, generalizations), and the third level, the most complex, is “extrapolation,” which involves making predications or estimates based on the information. 

Comprehension is different from knowledge in that knowledge implies merely remembering – whether a definition, a specific fact, or even a more complex statement (such as remembering what the theory of evolution entails).  To remember the details of a theory about evolution surely implies comprehension of what the terms mean, but still this action is merely a recall of knowledge committed to memory.  Comprehension on the other hand implies an action beyond merely memorizing.  You just have to understand a thing in itself – and, says Bloom – be able to demonstrate that you understand it by “demonstrating its use.” 

To show that you comprehend something, you need to be able to do something with it – to put it in your own words, to show that you can extrapolate from it, etc.

But to demonstrate the next level of intellectual abilities and skills, Application, you must be able to apply your knowledge of a theory or technique to a problem in a new situation.  This is a tremendously important educational objective for Bloom, and he writes for several pages about this point.  Again, you can almost hear him trying to persuade those who would teach and assess only knowledge to adapt more far-sighted educational objectives, such as application.

It strikes me that much of math education falls under both knowledge and application: the understanding of new theorems or rules and then learning to apply these in different situations.

Next is Analysis, a familiar one to English Language Arts teachers.  The use of analysis is in breaking down a “communication” so that it is better understood: its hierarchy of ideas, and/or the relationship between the ideas.  The whole idea is to clarify a communication of some kind – to explain how it communicates its message effectively.  Bloom offers a useful differentiation: comprehension is about understanding the message, while analysis is about understanding the message and the form.  Analysis is broken down into:

  • Analysis of elements – recognizing unstated assumptions; distinguishing facts from hypotheses.
  • Analysis of relationships – this is the analysis of the connections and interactions between the different parts of a communication: checking the consistency between the hypothesis and the given information; understanding the relations between the ideas in a passage.
  • Analysis of organizational principles – this means seeing pattern and form in a communication and making explicit its meaning; or understanding the techniques that are used, for example in a persuasive advertisement.

It strikes me that as defined by Bloom, analysis is largely aimed at understanding the workings of a communication – an article, or an essay – and thus it is a natural fit for English Language Arts.  Bloom reminds us that between analysis and comprehension “no clear lines can be drawn”; he also mentions that analysis can be an end in its own rite, but is better thought of as an aid to either comprehension (better understanding something) or evaluation, both of which seem like more holistic objectives.


In this step, you not only understand how all the parts fit together, but you actually put parts together yourself to form a whole.  Again, Bloom is sensitive to the blurring of the lines between categories.  He cites the example of an essay question: Even if the question calls for only analysis or even a recitation proving comprehension, does not the act of writing an “original” essay response represent a kind of synthesis?  No, says Bloom – because your response is not to be considered “original.” As a result, Bloom classifies three types of synthesis, all of which represent something new or unique:

  • Production of a unique communication
  • Production of a plan, or proposed set of operations
  • Derivation of a set of abstract relations – this is the ability to create an appropriate hypothesis, for example, based on an analysis of factors, and to modify the hypothesis in light of new information.

The last and highest level of the taxonomy is Evaluation.  This is the ability to judge the value of material or methods for a given purpose.  This divides into:

  • Judgments in terms of internal evidence – judging the accuracy of a communication based on internal logic, consistency, and other internal criteria.
  • Judgments in terms of external criteria – the ability to compare major works against each other, for instance.  

Once again, Bloom is cautious about seeing the taxonomy in too hierarchical a fashion.  Although evaluation is placed last because it largely includes the other educational goals within it, “[evaluation] is not necessarily the last step in thinking or problem solving.  It is quite possible that the evaluative process will in some cases be the prelude to the acquisition of new knowledge, a new attempt at comprehension or application, or a new analysis and synthesis” (185).

Bloom also distinguishes between evaluations and opinions, which he says are often reflexive, egotistical, and with little basis in much cognitive activity whatsoever.  Evaluations are more conscious and are based less on intuition than on comprehension and analysis.  He also touches on a subtle point, writing that education in a democracy is often “extremely cautious” about asking students to evaluate in any meaningful sense – this is, for Bloom, a result of democratic respect for an individual being able to make his own choices, and schools being concerned about these individual students not yet having a real sense of the alternatives.  I am not quite sure I know what he is specifically talking about, but I have a feeling he means that schools are more comfortable asking for evaluations based on internal consistency (a piece’s own logic and purpose) rather than asking students to pass judgment, for example, on some work of art that is in the curriculum, or on some political ideal that is clearly cherished by the school community.  I thought this was an interesting observation, if a little obscure phrased.


In the end, I found the original Bloom’s Taxonomy to be more detailed, more comprehensive, and more subtle about the distinctions between the different levels of objectives than I thought.  What I will take away from this reading is a renewed appreciation for disciplinary knowledge, an understanding of the importance of precision in ordering one’s objectives and curriculum, and an appreciation for the various types of educational goals available – and necessary – to pursue.

As this excellent article puts it: 

“As the authors themselves point out, all too frequently our descriptions of the behavior we want our students to achieve are stated as nothing but meaningless platitudes and empty cliches. (p. 4) If our educational objectives, they continue, are actually to give direction to the activities of both students and teachers, we must ‘tighten’ our language by making the terminology with which we express our aims more clear and meaningful.”

On the other hand, one salient critique of the structure of the taxonomy comes from well-known educator Ron Berger: 

“For me, the root problem with the framework is that it does not accurately represent the way that we learn things. We don’t start by remembering things, then understand them, then apply them, and move up the pyramid in steps as our capacity grows. Instead, much of the time we build understanding by applying knowledge and by creating things.”

In other words, we develop knowledge – of processes, for example – through trial and error.  We learn by doing.  This is a valid point – but it’s one that is aimed more appropriately at the pictorial and simplified view of the taxonomy, rather than Bloom’s original, more subtle book.  Once again, in the quote I cited above – and in many other places in the book – Bloom underscores the back-and-forth, non-linear nature of true learning: 

“[Evaluation] is not necessarily the last step in thinking or problem solving.  It is quite possible that the evaluative process will in some cases be the prelude to the acquisition of new knowledge . . .”

This view – that we should begin by trying something first, is well expressed by a Grant Wiggins post on misunderstandings of the taxonomy:

Some teachers make the argument that one should begin at the application state – creating an authentic, meaningful problem for students to solve, before introducing the means to solve it – the knowledge necessary – later on.  The goal of this is to build interest and curiosity and to create a motivation to learn information.

Either way, I developed an appreciation, once again, for going back to the source and reading the original material.  I’ll certainly never look at the classic simplified pyramid version of the taxonomy in the same way again. 

Speaking of which, I’d be remiss in this post if I didn’t mention the obvious and well-known fact that a revised taxonomy was published in 2001 and represents a very interesting reorganization.  I’ll have to review this in a subsequent post.

In the meantime, reading Bloom wasn’t especially revelatory, but more a confirmation:  That the closer we can get to real specificity in our ed goals, the better the outcome – the more hope we have of getting students to succeed at it.  Bloom does a nice job balancing his approach between knowledge and skills, and, while there are surely places to critique the taxonomy, it surely represents an important milestone in the development of educational curriculum and assessment.