The rapid increase in demand for American Sign Language (ASL) instruction between 1998 and 2002 created pervasive challenges in effectively assessing and documenting ASL learner performance. To address these challenges, we designed and developed the Avenue ASL e-assessment environment: an integrated, network-based software system to capture, evaluate, and manage ASL learner performances. In this paper, we present a design overview of the Avenue ASL system and use a lens of design-based research to examine how the theoretical foundations of the project have been enhanced through an iterative continuation of theory, design, and implementation research. The paper concludes with a discussion of potential further design applications, beyond ASL.