Online learning is an important and rapidly growing area, and asynchronous discussions are a vital component of online courses. This doctoral study examined the influence of discussion moderator messages, specifically messages with direct instruction content, had on those discussions. This study obtained data from content analysis of course discussions. The subjects for this study were the instructor and all 15 students enrolled in a fully-online graduate course at a large, public university medical center. The study found that the direct instruction content of an instructor message influenced students replying to that instructor message as well as students reading other student replies to that instructor message. The current study found that the direct instruction content of the instructor message may also influence students reading an instructor message and students responding to other replies to that instructor message. Instructors can use these findings to more effectively moderate their online discussions. [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.]