Valid inferences on teaching drawn from students' test scores require that tests are sensitive to the instruction students received in class. Accordingly, measures of the test items' instructional sensitivity provide empirical support for validity claims about inferences on instruction. In the present study, we first introduce the concepts of absolute and relative measures of instructional sensitivity. Absolute measures summarize a single item's total capacity of capturing effects of instruction, which is independent of the test's sensitivity. In contrast, relative measures summarize a single item's capacity of capturing effects of instruction relative to test sensitivity. Then, we propose a longitudinal multilevel item response theory model that allows estimating both types of measures depending on the identification constraints.