You have probably seen a sentence like ‘By the end of this unit, students will be able to explain ~’ at the start of a syllabus or textbook. Why do they bother writing it as an action, such as ‘will be able to explain’ or ‘will be able to compare,’ instead of ‘know’ or ‘understand’? At its root lies a framework that sorts learning into levels. It is ‘Bloom’s Taxonomy of Educational Objectives (Bloom’s Taxonomy).’
Put simply, Bloom’s Taxonomy of Educational Objectives refers to ‘a framework that arranges, in order from the easiest level to the hardest, the thinking skills a lesson aims to develop.’ The American educational psychologist Benjamin Bloom published it with fellow researchers in 1956 in a book titled “Taxonomy of Educational Objectives: The Cognitive Domain”. It began from the concern that every university used different standards when writing exam questions, so a common language was needed.
In this article, we will go step by step through what Bloom’s Taxonomy is, the six levels it first introduced, the revised edition of 2001, and how to use it in teaching and studying.
Bloom’s Taxonomy: a ladder that measures the depth of thinking
What Is Bloom’s Taxonomy?
Bloom and his colleagues divided the abilities that schools aim to develop into three broad domains. They then started by building detailed levels for the domain of thinking with the mind.
- Cognitive Domain: Deals with thinking abilities such as remembering, understanding, and judging.
- Affective Domain: Deals with abilities related to the heart, such as interests, attitudes, and values. David Krathwohl and others organized it separately in 1964.
- Psychomotor Domain: Deals with abilities that use the body, such as playing a musical instrument or handling lab equipment. Other scholars created its levels in the early 1970s.
When people say ‘Bloom’s Taxonomy,’ they usually mean the levels of the cognitive domain among these. Because it carries the idea that you must stand on the lower levels before you can climb to the higher ones, it is often compared to a ladder or a staircase.
The pyramid diagram commonly seen today was not in Bloom’s book; other people drew it later to make the idea easy to grasp. Bloom himself only described the levels as a cumulative structure built up in sequence and did not emphasize a shape that narrows toward the top.
The Original Six Levels
The 1956 edition divided the cognitive domain into six levels. Each level was given a noun as its name.
(1) Levels That Lay the Foundation
At the very bottom is Knowledge, recalling facts or terms. Above it, Comprehension is the level of explaining what you have learned in your own words, and Application is the level of using a learned principle in a new situation.
(2) Levels of Deep Thinking
Analysis is the level of breaking content into parts and examining how they relate to one another. Synthesis is the level of combining several elements to create a new whole, and Evaluation, at the very top, is the level of setting criteria and judging value.
(3) Seeing the Difference Through Questions
Even when reading the same novel, ‘What is the main character’s name?’ asks for knowledge, while ‘Was the main character’s choice right?’ asks for evaluation. Knowing the levels lets you gauge how deep the questions you ask really go.
At the time, a way of referring to the first three of these six levels as lower-order thinking and the last three as higher-order thinking also spread. Reflection that school exams leaned too heavily on memorization gained strength from this distinction.
What Changed in the 2001 Revision
This framework, widely used for 45 years, was revised and republished in 2001 by Bloom’s former student Lorin Anderson, together with Krathwohl and others.
[Change 1] From nouns to verbs
- Remember · Understand · Apply: The level names were changed to verbs describing what students actually do.
- Analyze · Evaluate · Create: Synthesis was changed to Create and placed at the very top, above Evaluate.
[Change 2] Separating the types of knowledge
- Knowledge Dimension: Knowledge was divided into four types (factual, conceptual, procedural, and metacognitive) so that ‘what’ is being learned is considered as well.
When the thinking processes and the types of knowledge are combined in rows and columns like this, you can pinpoint more precisely which cell of the table a lesson’s goal falls into. For example, ‘Explain the process of photosynthesis in order’ falls in the cell for understanding conceptual knowledge, while ‘Design a plant-growing experiment yourself’ falls in the cell for creating procedural knowledge.
How to Use It in Teaching and Studying
Bloom’s Taxonomy is not just a tool for teachers; it is also a useful map for people who study on their own. When using it, it helps to keep the following points in mind.
- Write goals as actions (Action Verbs): Instead of ‘know,’ write goals with verbs you can check, such as ‘list,’ ‘compare,’ or ‘design.’
- Match goals and assessment (Alignment): If you taught analysis, the test should also be designed to ask for analysis, not simple memorization.
- Broaden the depth of questions (Questioning): Do not stop at fact-checking questions; expand to questions that ask for reasons, judgments, and new ideas.
- Do not be bound by the order (Flexibility): Also keep in mind the criticism that in real learning, the levels do not come in strict sequence but grow as you move back and forth among them.
Not stopping at memorizing, but understanding, trying it out, weighing it, and making something new: that is the first step toward deep learning.
