Existing reading assessments have increasingly been criticized by researchers, educators, and policy makers, especially regarding their coverage, utility, and authenticity (e.g., Magliano, Millis, Ozuru, & McNamara, 2007; Pellegrino, Chudowsky, & Glaser, 2001; Rupp, Ferne, & Choi, 2006). Specifically, there is concern that current assessments often: are poorly aligned with contemporary theoretical constructs and empirical findings pertaining to reading processes and development; are insufficiently sensitive for detecting changes in the kinds of skills that are targeted by interventions; use mainly multiple-choice formats that emphasize strategic reasoning rather than understanding of the text; provide little diagnostic information for guiding instruction; and measure comprehension using tasks and texts that do not represent the full range of the purposeful literacy activities of 21st Century reading. In view of the foregoing criticisms, it is clear that new reading assessments are needed and desired by educators and researchers. These new assessments should draw upon the lessons that have been learned from prior experiences in both classroom and laboratory, over the past several decades. Our aim is to integrate and extend strengths of past approaches in an innovative way, yet adhere to rigorous design principles that will ensure feasible implementation, good construct coverage, and strong psychometric properties. The instruments' validity and educational utility will also be enhanced, if based on contemporary theory and research on reading, learning, and instruction. [This manuscript is an early draft of a paper published in: Miller, B., Cutting, L., & P. McCardle (Eds), "Unraveling Reading Comprehension: Behavioral, Neurobiological, and Genetic Components," (pp. 100-111). Baltimore, MD: Brookes Publishing.]