Bloom's Taxonomy of Educational Objectives

One of the most widely used ways of organizing levels of expertise is according to Bloom's Taxonomy of Educational Objectives. (Bloom et al., 1994; Gronlund, 1991; Krathwohl et al., 1956.) Bloom's Taxonomy (Tables 1-3) uses a multi-tiered scale to express the level of expertise required to achieve each measurable student outcome. Organizing measurable student outcomes in this way will allow us to select appropriate classroom assessment techniques for the course.

There are three taxonomies. Which of the three to use for a given measurable student outcome depends upon the original goal to which the measurable student outcome is connected. There are knowledge-based goals, skills-based goals, and affective goals (affective: values, attitudes, and interests); accordingly, there is a taxonomy for each. Within each taxonomy, levels of expertise are listed in order of increasing complexity. Measurable student outcomes that require the higher levels of expertise will require more sophisticated classroom assessment techniques.

The course goal in Figure 2--"student understands proper dental hygiene"--is an example of a knowledge-based goal. It is knowledge-based because it requires that the student learn certain facts and concepts. An example of a skills-based goal for this course might be "student flosses teeth properly." This is a skills-based goal because it requires that the student learn how to do something. Finally, an affective goal for this course might be "student cares about proper oral hygiene." This is an affective goal because it requires that the student's values, attitudes, or interests be affected by the course.
 

Table 1: Bloom's Taxonomy of Educational Objectives for Knowledge-Based Goals

LEVEL OF EXPERTISE	DESCRIPTION OF LEVEL	EXAMPLE OF MEASURABLE STUDENT OUTCOME
1. KNOWLEDGE	Recall, or recognition of terms, ideas, procedure, theories, etc.	When is the first day of Spring?
2. COMPREHENSION	Translate, interpret, extrapolate, but not see full implications or transfer to other situations, closer to literal translation.	What does the summer solstice represent?
3. APPLICATION	Apply abstractions, general principles, or methods to specific concrete situations.	What would Earth's seasons be like in specific regions with a different axis tilt?
4. ANALYSIS	Separation of a complex idea into its constituent parts and an understanding of organization and relationship between the parts. Includes realizing the distinction between hypothesis and fact as well as between relevant and extraneous variables.	Why are seasons reversed in the southern hemisphere?
5. SYNTHESIS	Creative, mental construction of ideas and concepts from multiple sources to form complex ideas into a new, integrated, and meaningful pattern subject to given constraints.	If the longest day of the year is in June, why is the northern hemisphere hottest in August?
6. EVALUATION	To make a judgment of ideas or methods using external evidence or self-selected criteria substantiated by observations or informed rationalizations.	What would be the important variables for predicting seasons on a newly discovered planet?

Table 2: Bloom's Taxonomy of Educational Objectives for Skills-Based Goals

LEVEL OF EXPERTISE	DESCRIPTION OF LEVEL	EXAMPLE OF MEASURABLE STUDENT OUTCOME
PERCEPTION	Uses sensory cues to guide actions	Some of the colored samples you see will need dilution before you take their spectra. Using only observation, how will you decide which solutions might need to be diluted?
SET	Demonstrates a readiness to take action to perform the task or objective	Describe how you would go about taking the absorbance spectra of a sample of pigments?
GUIDED RESPONSE	Knows steps required to complete the task or objective	Determine the density of a group of sample metals with regular and irregular shapes.
MECHANISM	Performs task or objective in a somewhat confident, proficient, and habitual manner	Using the procedure described below, determine the quantity of copper in your unknown ore. Report its mean value and standard deviation.
COMPLEX OVERT RESPONSE	Performs task or objective in a confident, proficient, and habitual manner	Use titration to determine the Ka for an unknown weak acid.
ADAPTATION	Performs task or objective as above, but can also modify actions to account for new or problematic situations	You are performing titrations on a series of unknown acids and find a variety of problems with the resulting curves, e.g., only 3.0 ml of base is required for one acid while 75.0 ml is required in another. What can you do to get valid data for all the unknown acids?
ORGANIZATION	Creates new tasks or objectives incorporating learned ones	Recall your plating and etching experiences with an aluminum substrate. Choose a different metal substrate and design a process to plate, mask, and etch so that a pattern of 4 different metals is created.

Table 3: Bloom's Taxonomy of Educational Objectives for Affective Goals

LEVEL OF EXPERTISE	DESCRIPTION OF LEVEL	EXAMPLE OF MEASURABLE STUDENT OUTCOME
RECEIVING	Demonstrates a willingness to participate in the activity	When I'm in class I am attentive to the instructor, take notes, etc. I do not read the newspaper instead.
RESPONDING	Shows interest in the objects, phenomena, or activity by seeking it out or pursuing it for pleasure	I complete my homework and participate in class discussions.
VALUING	Internalizes an appreciation for (values) the objectives, phenomena, or activity	I seek out information in popular media related to my class.
ORGANIZATION	Begins to compare different values, and resolves conflicts between them to form an internally consistent system of values	Some of the ideas I've learned in my class differ from my previous beliefs. How do I resolve this?
CHARACTERIZATION BY A VALUE OR VALUE COMPLEX	Adopts a long-term value system that is "pervasive, consistent, and predictable"	I've decided to take my family on a vacation to visit some of the places I learned about in my class.

To determine the level of expertise required for each measurable student outcome, first decide which of these three broad categories (knowledge-based, skills-based, and affective) the corresponding course goal belongs to. Then, using the appropriate Bloom's Taxonomy, look over the descriptions of the various levels of expertise. Determine which description most closely matches that measurable student outcome. As can be seen from the examples given in the three Tables, there are different ways of representing measurable student outcomes, e.g., as statements about students (Figure 2), as questions to be asked of students (Tables 1 and 2), or as statements from the student's perspective (Table 3). You may find additional ways of representing measurable student outcomes; those listed in Figure 2 and in Tables 1-3 are just examples.

Bloom's Taxonomy is a convenient way to describe the degree to which we want our students to understand and use concepts, to demonstrate particular skills, and to have their values, attitudes, and interests affected. It is critical that we determine the levels of student expertise that we are expecting our students to achieve because this will determine which classroom assessment techniques are most appropriate for the course. Though the most common form of classroom assessment used in introductory college courses--multiple choice tests--might be quite adequate for assessing knowledge and comprehension (levels 1 and 2, Table 1), this type of assessment often falls short when we want to assess our students knowledge at the higher levels of synthesis and evaluation (levels 5 and 6).4

Multiple-choice tests also rarely provide information about achievement of skills-based goals. Similarly, traditional course evaluations, a technique commonly used for affective assessment, do not generally provide useful information about changes in student values, attitudes, and interests.

Thus, commonly used assessment techniques, while perhaps providing a means for assigning grades, often do not provide us (or our students) with useful feedback for determining whether students are attaining our course goals. Usually, this is due to a combination of not having formalized goals to begin with, not having translated those goals into outcomes that are measurable, and not using assessment techniques capable of measuring expected student outcomes given the levels of expertise required to achieve them. Using the CIA model of course development, we can ensure that our curriculum, instructional methods, and classroom assessment techniques are properly aligned with course goals.

Note that Bloom's Taxonomy need not be applied exclusively after course goals have been defined. Indeed, Bloom's Taxonomy and the words associated with its different categories can help in the goals-defining process itself. Thus, Bloom's Taxonomy can be used in an iterative fashion to first state and then refine course goals. Bloom's Taxonomy can finally be used to identify which classroom assessment techniques are most appropriate for measuring these goals.

References

Bloom, B. S., Englehart, M. D., Furst, E. J., Hill, W. H., & Krathwohl, D. R. (1956). The Taxonomy of educational objectives, handbook I: The Cognitive domain. New York: David McKay Co., Inc.

Gronlund, N. E. (1991). How to write and use instructional objectives (4th ed.). New York: Macmillan Publishing Co.

Krathwohl, D.R., Bloom, B.S., & Masia, B.B. (1964). Taxonomy of educational objectives, the classification of educational goals, handbook II: Affective domain. New York: David McKay Co., Inc.