The Assistant Masters' and Mistresses' Association (AMMA) was formed in 1978 by the merger of the Association of Assistant Mistresses and the Assistant Masters' Association. In 1993 it became the Association of Teachers and Lecturers. Both the Association of Assistant Mistresses and the Assistant Masters' Association had been a member of the Joint Committee of the Four Secondary Associations, more commonly known as the "Joint Four" from 1917-1978.
Reference: IAAM year books and other publications in MSS.453; A.M.A.: Seventy Years of Progress (London, AMA, [1961]).
From the guide to the Papers of the Assistant Masters' and Mistresses' Association, 1974-1988, (Modern Records Centre, University of Warwick Library)