Quality and uselessness

It is good to find Peter Mann ("Trust to your tacit knowledge", Research, THES, April 17) distinguishing between "explicit knowledge" and "tacit knowledge"; but why stop there?

It is important, too, to identify "conceptual knowledge". Indeed, the ultimate aim of research is usually "conceptual development and improved understanding". Tacit knowledge, or "know-how", which (like common sense and best practice) is acquired through successful experiences, and it certainly "pervades the shop floor"; but it is "understanding" that underpins unprecedented innovations, enables us to get them right and keeps industry ahead.

The distinctions between "factual knowledge", "know-how" and "understanding" are important in education, too, because the appropriate teaching methods are different in each case.

John Sparkes Hemel Hempstead