The library literature evaluating the efficacy of online tutorial methods and delivery tools is a valuable resource for librarians looking for information to inform their choices for developing asynchronous online instruction. This literature, however, examines a wide variety of delivery tools, methods, and student populations. As a result, it is difficult to draw definitive conclusions about any one tutorial tool or method. This article compares selected research and concludes that the consensus in the literature suggests that applying adult learning principles to library tutorials has a larger impact on effective online instruction than the individual tool.