“The paper documents a pilot user test with a small group of K-12 teachers-in-training. The users were asked to use the portal to locate primary source materials for use in the classroom. The results highlight the challenges posed by aggregations of heterogeneous metadata for both users and service providers. Areas for further investigation and approaches for more in-depth studies are suggested.” (Sarah L. Shreeves and Christine M. Kirkham – Journal of Digital Information 5.3)