ABSTRACT. An overarching motivation driving my research has been to further our theoretical understanding of how readers successfully comprehend challenging text. This presentation will describe the theoretical origins of this research program, and my quest to understand comprehension processes through the use of technology. One approach that I have taken to better understand comprehension is to attempt to change it. For example, iSTART was developed to provide students with instruction and practice on how to explain text and more effectively make use of limited prior knowledge. Coh-Metrix was developed to measure, and in turn facilitate manipulations of text cohesion and text ease. In addition, we have developed technologies to measure and change writing quality, relations between ideas, and emerging text comprehension. More recently, our attention has turned to comprehension of multiple documents. Understanding relations between documents and how comprehension emerges when reading multiple sources is important educationally, and socially, where the internet provides a continuous stream of reliable and unreliable sources. Across these topics, my collaborators and I have conducted numerous experimental studies, but a central theme to my work has been the use of technology. This presentation will describe these technologies, including game-based tutoring systems, natural language processing, and computational simulations and how they have informed my theoretical and practical understandings of language, comprehension, social interactions, and cognition.