The recent deluge of published studies employing sentences or connected discourse as the unit of study has left unsolved the question of whether the two types of materials are essentially similar or importantly different. An understanding of this issue is crucial to theory, since the existence of major psychological differences between the comprehension, learning, and memory of sentence lists and connected discourse would make a unified theory covering both types of materials exceedingly difficult to formulate. While offering no final resolution of the issue, the present paper examines the evidence, considers the implications of several major theoretical developments, and poses questions amenable to experimentation. It is hoped that the paper will serve as a springboard to a higher level of understanding of how people process these two common types of experimental materials. A list of references is included. (Author/JM)