Table of Specifications

The table of specifications (TOS) is a tool used to ensure that a test or assessment measures the content and thinking skills that the test intends to [Page 1655]measure. Thus, when used appropriately, it can provide response content and construct (i.e., response process) validity evidence. A TOS may be used for large-scale test construction, classroom-level assessments by teachers, and psychometric scale development. It is a foundational tool in designing tests or measures for research and educational purposes.

The primary purpose of a TOS is to ensure alignment between the items or elements of an assessment and the content, skills, or constructs that the assessment intends to assess. That is, a TOS helps test constructors to focus on issue of response content, ensuring that the test or assessment measures what it intends to measure. For example, if a teacher is interested in assessing the students’ understanding of lunar phases, then it would be appropriate to have a test item asking them to draw the phases of the moon. However, a test item asking them to identify the first person to walk on the moon would not have the same content validity to assess students’ knowledge of lunar phases.

In addition, a TOS can also be used to provide response process validity evidence for test constructors. Response process refers to the kind of thinking that is expected of the test taker in completing the assessment. For the lunar phases, for example, a teacher may expect students to memorize the phases of the moon and therefore a knowledge-level (relying on recognition or memory) question would be appropriate. Alternatively, if the teacher taught the lessons such that students tracked the moon for a month, developed lunar journals, and discussed the reasons for the different phases, then the assessment should target higher level thinking such as analysis, evaluation, and synthesis. As such, asking students to draw a model of the lunar phases with annotated explanations would be better aligned to the kind of thinking that students experienced during instruction.

The TOS is typically constructed as a table that includes key information to help teachers align the learning objectives that represent the content and cognitive levels intended for students to achieve with class time spent and the number of test items. Table 1 provides an example of a TOS for a chapter test on “New Ideas for a New Century,” from Molefi Kete Asante’s (1995) African American History: A Journey of Liberation. This entry explored the roles of prominent African American leaders from 1895 to 1919. Before constructing the TOS, the teacher decided the total number of items to include (i.e., 10) and quantity and type of those items (i.e., five multiple-choice and five short answers), and the decision was made based on the time allocated for students to complete the test and students’ general test-taking abilities. Next, the teacher referred to the lesson plans and notes to determine the content in columns A–C (i.e., day, learning objectives, time spent on objective). To calculate the percentage of class time for each objective (column D), the teacher divided the minutes spent teaching each objective (column C) by the total minutes for the unit and multiplied by 100. Determining the percentage of time spent in class on each objective is one approach to identifying how many items on the test should address any particular objective and enhances test content validity evidence.

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