The collection represents the data that Roe (Mrs. George Gaylord Simpson) collected on 64 scientists for her 1953 book, The Making of a Scientist. The material for each scientist includes transcripts of interviews, Rorschach and Thematic Apperception Tests, personal data, reprints of the scientist's publications, and letters several years afterward the interview asking for additional information. There are also photostats of letters and notes by the scientists dating earlier than 1949; holders of the originals of these letters is unknown.