Table of Specifications
A Table of Specifications is a blueprint for an objective selected response assessment. The purpose is to coordinate the assessment questions with the time spent on any particular content area, the objectives of the unit being taught, and the level of critical thinking required by the objectives or state standards. The use of a Table of Specifications is to increase the validity and quality of objective type assessments. The teacher should know in advance specifically what is being assessed as well as the level of critical thinking required of the students. Tables of Specifications are created as part of the preparation for the unit, not as an afterthought the night before the test. Knowing what is contained in the assessment and that the content matches the standards and benchmarks in level of critical thinking will guide learning experiences presented to students. Students appreciate knowing what is being assessed and what level mastery is required.
Any question on an assessment should require students to do three things: first, access information on the topic of the question. Second, use that knowledge to complete critical thinking about the information. Third, determine the best answer to the question asked on the assessment.
A Table of Specifications is a two-way chart which describes the topics to be covered in a test and the number of items or points which will be associated with each topic. Sometimes the types of items are described as well.
The purpose of a Table of Specifications is to identify the achievement domains being measured and to ensure that a fair and representative sample of questions appear on the test.
As it is impossible, in a test, to assess every topic from every aspect, a Table of Specifications allows us to ensure that our test focuses on the most important areas and weights different areas based on their importance / time spent teaching. A Table of Specifications also gives us the proof we need to make sure our test has content validity.
Tables of Specifications are designed based on:
- course objectives
- topics covered in class
- amount of time spent on those topics
- textbook chapter topics
- emphasis and space provided in the text
A Table of Specification could be designed in 3 simple steps:
1. identify the domain that is to be assessed
2. break the domain into levels (e.g. knowledge, comprehension, application …)
3. construct the table
The more detailed a table of specifications is, the easier it is to construct the test.
How to Prepare a Table of Specification?
The following is a simplified method of preparing a Table of Specifications.
1. List all the topics that are included in the subject or course.
2. Assign corresponding percentages based on the professional requirements or
institutional requirements. Below is an example:
Subject - CLINICAL CHEMISTRY 2
a. automation - 20 %
b. electrolytes - 15 %
c. enzymology - 25 %
d. endocrinology - 20 %
e. toxicology - 20 %
This gives a total of 100 %
3. Decide on the number of items that you would like the test to be. Let's say you
wanted a 160 item - test; the number of items per topic would then be:
a. automation - 20 % - 32
b. electrolytes - 15 % - 24
c. enzymology - 25 % - 40
d. endocrinology - 20 % - 32
e. toxicology - 20 % - 40
This gives a total of 160 items.
4. Assign the specific type of question you would like to ask depending on what
skill or cognitive learning, you would like to emphasize. For example, you would
like to emphasize the principles in automation, then you may prepare the
questions this way:
a. automation - 32 items
Essay = 10 questions
Identification = 12 questions
Multiple choice = 20 questions
This gives a total of 32 items.
This also is done with the rest of the topics.