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:
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.