nmahmain copy 39088020680419 Purchased from the NMAH Library Endowment. How ed tech was born: Twentieth-century teaching machines-from Sidney Pressey's mechanized test-giver to B. F. Skinner's ...

IIIF provides researchers rich metadata and media viewing options for comparison of works across cultural heritage collections. Visit the IIIF page to learn more. In the years following World War II, ...