Design methods are procedures, techniques, aids, or tools for designing. They offer a number of different kinds of activities that a designer might use within an overall design process. Conventional procedures of design, such as drawing, can be regarded as design methods, but since the 1950s new procedures have been developed that are more usually grouped together under the name of "design methods". What design methods have in common is that they "are attempts to make public the hitherto private thinking of designers; to externalise the design process". Design methodology is the broader study of method in design: the study of the principles, practices and procedures of designing. Design methods originated in new approaches to problem solving developed in the mid-20th Century, and also in response to industrialisation and mass-production, which changed the nature of designing. A "Conference on Systematic and Intuitive Methods in Engineering, Industrial Design, Architecture and Communications", held in London in 1962 is regarded as a key event marking the beginning of what became known within design studies as the "design methods movement", leading to the founding of the Design Research Society and influencing design education and practice. Leading figures in this movement in the UK were J. Christopher Jones at the University of Manchester and L. Bruce Archer at the Royal College of Art. The movement developed through further conferences on new design methods in the UK and USA in the 1960s. The first books on rational design methods, and on creative methods also appeared in this period. New approaches to design were developing at the same time in Germany, notably at the Ulm School of Design (Hochschule für Gestaltung–HfG Ulm) (1953–1968) under the leadership of Tomás Maldonado. Design teaching at Ulm integrated design with science (including social sciences) and introduced new fields of study such as cybernetics, systems theory and semiotics into design education. Bruce Archer also taught at Ulm, and another influential teacher was Horst Rittel.