THE PERSEUS DIGITAL LIBRARY (PDL) IS ONE OF THE primary digital resources f
or the humanities. Under continuous development since 1987, the project has
included an ongoing evaluation component that aims to understand the effec
ts of access to digitized source materials in the humanities. A summary of
the PDL genesis and current status is given and the multifaceted and longit
udinal evaluation effort is described. A brief synthesis of results is prov
ided and reflections oil the evaluation along with recommendations for DL e
valuation ale given.