Colleen was a long-time high school physics and mathematics teacher and Modeler in Sacramento CA. She moved to AZ in 2001 to do graduate studies in physics education research focusing on Modeling classroom discourse. In 2007 she completed her PhD under the direction of David Hestenes. Se was an assistant professor of science education at Arizona State University until 2011 when she transitioned to a half-time research scientist position to become AMTA’s first Executive Officer. In 2014 she retired from ASU to devote her fully attention to AMTA. In 2017 she “retired” from the XO position and became AMTA’s first Senior Fellow. Colleen continues to write grants, conduct research, teach occasional courses in modeling and cognition, train workshop leaders, and publish on Modeling Instruction. Her current research interests are computational modeling, teacher leadership, out-of-field science teaching, and cognition in Modeling Instruction.