This dissertation reports the results of three studies and a pilot study. The first study was a Monte Carlo validation study that examined the accuracy of a new visual inspection method, the semi-interquartile range method. Results of the study indicated that this method had lower levels of power than a previously validated method, the conservative dual-criteria method. Based on these low levels of power, the semi-interquartile range is not an appropriate visual inspection method to use in applied settings. Therefore, the conservative dual-criteria method was used in the subsequent studies. Study 2 examined the accuracy of preservice teachers in implementing the conservative dual-criteria method. Although participants were significantly more accurate in implementing this method after receiving training on the method, the average accuracy rate in method implementation was still low (i.e., 44%). This low level of accuracy was likely due to participants' lack of integrity in implementing all of the steps of the visual inspection method; previous studies have not required participants to implement all of the steps (e.g., drawing criterion lines; Fisher, Kelly, and Lomas, 2003). Therefore, in Study 3, computer-generated criterion lines were included on student performance graphs instead of instructing participants to draw the lines. Study 3 expanded on the results of Study 2 by examining the impact of anecdotal information on participants' interpretation of single-case research design data. Results of Study 3 indicated that participants were significantly more accurate in data interpretation after receiving training on the conservative dual-criteria method. Additionally, participants were more accurate in data interpretation when anecdotal information and graphed student performance data were consistent than when anecdotal information and graphed student performance data were inconsistent. [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://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]