A Table of Specifications (TOS) is a two-way chart that describes the topics to be covered in a test and the number of items or points that will be associated with each topic. It is a tool that helps teachers align objectives, instruction, and assessment. The purpose of a TOS is to identify the achievement domains being measured and to ensure that a fair and representative sample of questions appear on the test. It allows teachers to construct a test that focuses on the key areas and weights those different areas based on their importance.

Tables of Specifications are typically designed based on the list of course objectives, the topics covered in class, the amount of time spent on those topics, textbook chapter topics, and the emphasis and space provided in the text. Three steps are involved in creating a TOS: identifying the domain that is to be assessed, breaking the domain into levels, and constructing the table. The more detailed a TOS is, the easier it is to construct the test.

The use of a TOS provides a strategy for teachers to improve the validity of the judgments they make about their students from test responses by providing content and response process evidence. It ensures that the test developed assesses the content taught and the learning experience given to the students. Moreover, it helps align the test with learning objectives and their cognitive levels. A TOS also enables teachers to allocate a specific amount of instructional time needed for each topic/SLOs and assess learning objectives that are actually included in the instructional process.