Yet there are books on memo-writing, on filing, on conduct of meetings and interviews, even on use of the telephone. They are usually written at a fairly elementary level, and the degree of time-and-place specificity that is feasible is strictly limited. It is the translation of the training function to the classroom that makes a market for written instruction in administrative practice; but the value of the one-to-one oral tradition, that enabled a flexible blend of specificity and generality, that taught as much by what was left unsaid as by what was said, that varied the syle to suit the persons concerned, has never been lost sight of, and few of such 'practical' books escape heavy criticism from practitioners