This meta-analysis of the experimental literature of distance education (DE) compares different types of interaction treatments (ITs) with other DE instructional treatments. ITs are the conditions or environments that are designed and arranged by teachers into DE courses. These treatments are intended to facilitate student-student (SS), student-teacher (ST), or student-content (SC) interactions. Seventy-four DE versus DE studies that contained at least one IT are included in the meta-analysis, which yield 74 achievement effects.