Response time is an important research topic in the field of psychometrics. This dissertation tries to explore some response time properties across several item characteristics and examinee characteristics, as well as the interactions between response time and response outcomes, using data from a statewide mathematics assessment in two grades. Several methods were adopted to investigate the timing properties, including multilevel linear modeling, latent growth curve modeling, differential response time index, and visual techniques. Results indicated that item characteristics and examinee groups differ in response time across grades, and examinees paced through the assessment very differently. Considering the results, it is hoped to help improve testing practices from the perspectives of test construction and fairness. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]