Articles, artifacts, audio cassette, historical documents, instruction system design handbooks, manuals, papers, photographs, publications, teaching aids and devices, and teaching methods handbooks, which document the pioneering audio tutorial system of instruction of Professor Samuel N. Postlethwait during the 1960s and early 1970s.

The conference programs, papers, information, lists of participants, and other material related to the Annual Audio-Tutorial Congress can be found in this series. There is also a binder containing a pictorial history of the Minicourse Development Project and additional random documents.