A table of specifications or TOS is a test map that guides the teacher in constructing a test. The TOS ensures that there is balance between items that test lower level thinking skills and those which test higher order thinking skills ( or alternatively, a balance between easy and difficult items) in the test. The simplest TOS consists of four (4) columns: (a) level of objective to be tested, (b) statement of objective, (c) item numbers where such an objective is being tested, and (d) Number of items and percentage out of the total for that particular objective. A prototype table is shown below:
In the table of specifications we see that there are five items that deal with knowledge and these items are items 1,3,5,7,9. Similarly, from the same table we see that five items represent synthesis, namely: 12, 14, 16, 18, 20. The first four levels of Bloom’s taxonomy are equally represented in the test while application (tested through essay) is weighted equivalent to ten (10) points or double the weight given to any of the first four levels. The table of specifications guides the teacher in formulating the test. As we can see, the TOS also ensures that each of the objectives in the hierarchy of educational objectives is well represented in the test. As such, the resulting test that will be constructed by the teacher will be more or less comprehensive. Without the table of specifications, the tendency for the test maker is to focus too much on facts and concepts at the knowledge level.