1. Some ideas in this paper were stimulated by Howard Rosenbrock’s earlier writings especially Rosenbrock, H. (1977). The Future of Control Automatica, 13, 389-392. I am grateful to H.M. Collins for discussions on the character of tacit knowledge.
2. Polanyi, M. (1962). Personal Knowledge Routledge and Kegan Paul, London. Chapters 4 and 5: Studies of scientific experiment replication also discovered the intangible character of tacit knowledge: Collins H.M. (1974). TEA Set: lacit Knowledge and Scientific Networks. Science Studies. 4, 165-186.
3. McKenna, R. (1963). The Sand, Victor Gollancz, London. This work’s relevance to work skills was first pointed out by Piore, M. (1968). On the Job Training and Adjustment to Technological Changes. The Journal of Human Resources, III, 4, 435-449.
4. Jones, B. (19/9). The Definition and Control of Occupational Tasks in the Process of Technological Change. Final Report to S.S.R.C., British Library, Boston Spa.
5. Different National on Use of New Production, Technology;Jones,1982