Interaction is a critical component of distance education and involves the transfer of information between the learner and content, learner and learner, or learner and instructor (Moore, 1989). Current distance education literature has examined the role of interaction, specifically learner-learner interaction, in learning and discussion design to enhance achievement. The purpose of this study was to compare the effects of restricted and traditional discussion boards on critical thinking and learning in a graduate-level online distance education course. Findings indicated improved critical thinking in the quality and preparation strategies of initial discussion board postings when participants' views of peer responses to discussion board questions were restricted until a predetermined date. Although the overall quality of subsequent postings was not affected, content analysis revealed a significant increase in discourse and revised opinions in the restricted format. (Contains 2 tables.)