Robert L. Hampelâ€™s 2014 edited collection of pieces by Paul Diederich, most of them unpublished, casts Diederich in a new light. The articles, reports, and memoranda reveal him and his work in writing assessment as deeply progressive, both in the educational and political sense. They call for a re-interpretation of his factoring of reader judgments (1961), his analytical scale for student essays (1966), and his measuring of student growth in writing (1974). The pieces also depict Diederich as an intricate and sometimes conflicted thinker, who always saw school writing performance and measurement in terms of the psychological, social, and ethical. He still has relevance today, especially for writing assessment specialists wrestling with current issues such as the testing slated for the Common Core State Standards.