A Revision of Bloom's Taxonomy: An Overview (part 1)

by David R. Krathwohl

David R. Krathwohl is Hannah Hammond Professor of
Education Emeritus at Syracuse University.

The taxonomy of educational objectives is  a framework for classifying statements of what we expect or intend  students to  learn  as  a result of instruction. The framework was conceived as a means of facilitating the exchange of test items among faculty  at various universities in order to create  banks of items,  each measuring the  same educational  objective. Benjamin S.  Bloom, then Associate Director of the Board of Examinations of the University of Chicago, initiated the idea, hoping that it  would reduce  the  labor  of preparing annual comprehensive examinations. To aid in his effort, he enlisted a group of measurement specialists  from across the United States, many of whom repeatedly faced the same problem. This group met about twice a year beginning in  1949 to consider progress, make revisions,  and plan the next steps. Their final draft was published in  1956 under the title,  Taxonomy qf Educational Objectives: The Classification of Edu-cational Goals. Handbook I:  Cognitive Domain (Bloom, Engelhart, Furst, Hill, & Krathwohl, 1956). 'Hereafter, this is referred  to as the original Taxono-my. The revision  of this  framework,  which is  the subject of this issue  of Theory Into Practice, was developed in much the same manner 45 years later (Anderson,  Krathwohl, et al., 2001). Hereafter, this is referred to as the revised Taxonomy.

Bloom saw the original Taxonomy as more than a measurement tool. He believed it could serve as a
* common language  about learning  goals to facili-tate communication across persons, subject matter, and grade levels;
* basis for determining for a particular course or curriculum the specific meaning of broad educa-tional goals, such as those found in the currently prevalent national, state, and local standards;
* means for determining the congruence of educa-tional objectives, activities, and assessments in a unit, course, or curriculum; and
* panorama of the range of educational possibili-ties against which the limited breadth and depth of any particular educational course or curricu-lum could be contrasted.

The Original Taxonomy
The original Taxonomy provided carefully developed definitions for each of the six major cat-egories  in  the  cognitive domain.  The categories were Knowledge, Comprehension, Application, Analysis, Synthesis, and Evaluation.  With the ex-ception of Application, each of these  was broken into subcategories.  The complete structure of the original Taxonomy is shown in Table 1.

Table 1
Structure of the Original Taxonomy
1.0 Knowledge
      1.10 Knowledge of specifics
              1.11 Knowledge of terminology
              1.12 Knowledge of specific facts
      1.20 Knowledge of ways and means of dealing with specifics
              1.21 Knowledge of conventions
              1.22 Knowledge of trends and sequences
              1.23 Knowledge of classifications and categories
              1.24 Knowledge of criteria
              1.25 Knowledge of methodology
      1.30 Knowledge of universals and abstractions in a field
              1.31 Knowledge of principles and generaliza-tions
              1.32 Knowledge of theories and structures
2.0 Comprehension
      2.1 Translation
      2.2 Interpretation
      2.3 Extrapolation
3.0 Application

4.0 Analysis
      4.1 Analvsis of elements
      4.2 Analysis of relationships
      4.3 Analysis of organizational principles
5.0 Synthesis
      5.1 Production of a unique communication
      5.2 Production of a plan, or proposed set of operations
      5.3 Derivation of a set of abstract relations
6.0 Evaluation
      6.1 Evaluation in terms of internal evidence
      6.2 Judgments in terms of external criteria

The categories were ordered from simple to complex and from concrete to abstract. Further, it was assumed that  the  original Taxonomy repre-sented a cumulative hierarchy; that is,  mastery of each simpler category was prerequisite to mastery of the next more complex one. At the time  it was introduced,  the term tax-onomy was unfamiliar as an education term.  Po-tential  users did not understand  what it  meant, therefore,  little attention was given to the original Taxonomy at first. But as readers  saw its  poten-tial, the framework became widely known and cit-ed, eventually being translated  into 22 languages. One of the most frequent uses of the original Taxonomy has been to  classify curricular objec-tives and test items  in order to show the breadth, or lack  of breadth,  of the  objectives and items across the spectrum of categories. Almost always, these  analyses have shown a heavy emphasis on objectives requiring  only recognition  or recall of information, objectives that fall in  the Knowledge category. But, it is objectives that involve the under-staniding and use of knowledge, those that would be classified in  the categories from Comprehension to Synthesis, that are usually considered the  most im-portant goals of education. Such analyses, therefore,
have repeatedly provided a basis for moving curricu-la and tests toward objectives that would be classi-fied in the more complex categories.

From One Dimension to Two Dimensions 

Objectives that  describe intended  learning outcomes as the  result  of instruction  are usually framed in terms of (a)  some subject matter content and  (b) a description of what is to be done with or to that content.
Thus, statements of objectives typically consist of a noun or noun phrase-the subject matter content-and a verb or verb phrase-the cognitive process(es). Consider, for example, the following objective: The student shall be able to remember the law of supply and demand in economics. "The student shall be able to"  (or "The learner will," or some other similar phrase) is common to all objec-tives  since an objective defines what students are expected to  learn.  Statements of objectives often omit "The student shall be able to"  phrase, speci-fyirig  just the  unique part (e.g.,  "Remember  the economics  law of supply and demand."). In  this forn  it is  clear that  the  noun phrase is  "law of supply and demand" and the verb is "remember."In the original Taxonomy, the Knowledge cate-gory embodied both noun and verb aspects. The noun or sabject matter aspect was specified in Knowledge's extensive subcategories. The verb aspect was includ-ed in the definition given to Knowledge in that the student was expected to be able to recall  or recog-nize knowledge. This brought unidimensionality to the framework at the cost of a Knowledge category that was dual in  nature and thus different from the other Taxonomic categories. This anomaly was elim-inated  in the  revised  Taxonomy by allowing these two aspects, the noun and verb, to form separate di-mensions, the noun providing the basis for the Knowl-edge dimension and the  verb forming the  basis for the Cognitive Process dimension.

The Knowledge dimension
Like the original, the  knowledge categories of the revised Taxonomy cut across subject matter lines.  The new Knowledge dimension, however, contains  four instead  of three  main categories. Three of them include the substance of the subcat-egories of Knowledge in  the original framework. But they were reorganized to use the terminology, and to recognize the distinctions of cognitive psy-chology that developed since the  original frame-work was devised. A fourth,  and new category, Metacognitive Knowledge,  provides a distinction that was not widely recognized at the time the orig-inal scheme was developed. Metacognitive Knowl-edge involves knowledge about cognition in general as well as awareness of and knowledge about one's own cognition (Pintrich,  this  issue).  It  is  of in-creasing  significance  as  researchers  continue to demonstrate the importance of students being made aware of their metacognitive activity, and then us-ing this knowledge to appropriately adapt the ways in  which they think and operate. The four catego-ries with their subcategories are shown in Table 2.

The Cognitive Process dimension
The original number of categories, six, was re-tained, but with important changes. Three categories were renamed,  the  order of two was interchanged, and those category names retained  were changed to verb form to fit the way they are used in objectives. The verb aspect of the  original Knowledge category was kept as the first of the six major cat-egories, but was renamed Remember. Comprehen-sion was renamed  because  one  criterion for selecting category labels was the use of terms that teachers  use in  talking  about their work. Because understand is a commonly used term in objectives, its lack of inclusion was a frequent criticism of the original Taxonomy. Indeed, the original group con-sidered using it, but dropped the idea after further consideration showed that when teachers say they want the student to "really" understand, they mean
anything from  Comprehension to  Synthesis. But, to the revising authors there seemed to be popular usage in which understand was a widespread syn-onym for comprehending. So, Comprehension, the second  of the  original categories,  was renamed Understand.

Table 2
Structure of the Knowledge Dimension of the Revised Taxonomy
A. Factual Knowledge - The basic elements that  stu-dents must know to be acquainted with a discipline or solve problems in  it.
     Aa. Knowledge of terminology
     Ab. Knowledge of specific details and elements
B. Conceptual Knowledge  - The interrelationships among the basic elements within a larger  structure that enable them to function together.
     Ba. Knowledge of classifications and categories
     Bb. Knowledge of principles and generalizations
     Bc. Knowledge of theories, models, and structures
C. Procedural Knowledge - How to do something; meth-ods of inquiry,  and criteria for using skills, algorithms, techniques,  and methods.
     Ca. Knowledge of subject-specific  skills and al-gorithms
     Cb. Knowledge of subject-specific  techniques and methods
     Cc. Knowledge of criteria for determining when to use appropriate procedures
D. Metacognitive Knowledge - Knowledge of cognition in  general as well as awareness  and knowledge of
one's own cognition.
    Da. Strategic knowledge
    Db. Knowledge about cognitive tasks, including appropriate contextual and conditional
knowledge
    Dc. Self-knowledge

Application, Analysis, and Evaluation were re-tained,  but in  their  verb forms  as Apply, Analyze, and Evaluate. Synthesis changed places with Evalu-ation and was renamed Create. All the original sub-categories were replaced  with gerunds, and called "cognitive processes." With these changes, the cate-gories and subcategories-cognitive processes-of the Cognitive Process dimension are shown in Table 3. Whereas the  six major categories  were given far more attention than the subcategories in the orig-inal  Taxonomy, in  the revision, the  19 specific cog-nitive processes within the  six cognitive  process categories receive the major emphasis. Indeed, the nature of the revision's six major categories emerg-es most clearly from the descriptions given the spe-cific cognitive processes. Together, these processes characterize each category's breadth and depth.