Some people need training because it is known (or safely assumed) that they lack particular knowledge or skills. In many situations, for example, it is a good bet that newly hired salespeople lack knowledge of the products sold by the company hiring them. It is not as good a bet that these same new hires are lacking in basic selling skills. Nor, in the case of commodity-like products, is it a good bet that they lack basic product knowledge. A person selling PCs at SEARS, for in- stance, probably won’t have much trouble making the transition to a Radio Shack store. It is also reasonable to assume that the introduction of a new system carries with it a requirement to train the users, especially if its functions are new or represent a radical departure from previous sys- tems. It is not as reasonable to assume that a person skilled at using Lotus 1-2-3 will require ex- tensive training before being able to use Microsoft Excel.