ABSTRACT
In applying any model of adoption, or sales, or whatever, there are two basic philosophies we may take for assigning values to the parameters of the model.
The first may be defined as the direct empirical approach, which requires sales to have occurred, and data to be available. The parameter values are then computed by the traditional curve fitting exercise such as that employed to fit the special theory of innovative behaviour to data (see Section 5.2.). Obviously the earliest this can be employed is during the test market (when the first sales, as such, occur). Thus it cannot be used during the major portion of the development programme.
