Memory-based and constructionist processes have both been proposed as essential components of the activation of concepts (e.g., propositions) and the establishment of meaningful connections between concepts during reading. In this article, we argue that a comprehensive theory of reading comprehension should include both sets of processes. In support of this view, we summarize the results of several studies that support the contribution of both processes during reading. In addition, we describe the conceptual framework of the Landscape Model, in which memory-based and constructionist processes are explicitly interconnected and dynamically interact in an account of reading comprehension.