Assessment instruments, such as the exams created by the ACS Exams Institute, consist of a number of cognitive tasks that are undertaken by the student whose knowledge is being measured. Cognitive load theory (CLT) provides a useful model for understanding the demands of any task - including exam items - in terms of the number of pieces of information in the working memory that are needed to carry out the task. Analysis of items on ACS Exams in light of CLT provides an additional measure of how student understanding of chemistry is linked to their cognitive development. This talk will present the methodology we use to assess the cognitive load of ACS Exams items and describe how this analysis can be utilized to maximize the information that may be obtained from test based measurement of student learning.