Dr. Shannon was employed as a Research Fellow at the Shell Centre for Mathematics Education, University Nottingham, England before moving her work to the University of California, Berkeley in 1994.

At the University of California, she developed performance assessments for the NSF‐funded Balanced Assessment project and the New Standards project. Her 1999 monograph, Keeping Score, was published by the National Research Council and drew on her work for Balanced Assessment and New Standards; addressing a variety of issues that are relevant to developing, administering, and scoring mathematics assessments. In this monograph she also develops the concept of “opportunity to perform” and explores its role in ensuring universal access to quality instruction.