ABSTRACT
All categorisation schemes can be separated into two components . One of these is the measurement of individual innovativeness, and the other is the formation of the various ~ategories of individuals - categories which represent differing degrees of innovativeness. All such schemes also associate the term 'innovators' with the highest degree of innovativeness, 'early adopters' or 'early majority' with tHe next highest, and so on down to the 'laggards'. While the actual terms used may differ, the basic cdncepts are remarkably similar. Furthermore all the schemes to be discussed here utilise the same fundamental measurement of individual innovativeness, and it is only in the second component - formation of categories - that differences emerge. It will subsequently be argued that all the schemes currently available involve an undesirable arbitrary element in this second component or procedure, and that a
Innovativeness is assumed to be a trait possessed, to a greater or lesser degree, by all members of a society, and as such usually becomes a continuous dependent variable in research studies. Innovativeness relates to when an individual adopts the innovation as compared with when the society as a whole adopts it. If an individual adopts soon after the innovation appears, and before the bulk of the population adopts the innovation, then it will be readily appreciated that this individual is more innovative than one who only adopts after two-thirds of his fellows have already done so. Measurement of innovativeness is therefore accomplished by observing when individuals adopt, aggregating these individual adoptions into a distribution, and comparing anyone individual's adoption date with the distribution. The first necessary items of information are the date an individual adopts, and the date the innovation was introduced. However this only provides a duration or elapsed time to adoption in isolation from other individuals, and says nothing about whether the individual was ahead or behind the majority. In order to effect this latter comparison, two other items are needed: the mean time of adoption for all individuals, and the standard deviation of the adopter distribution. The mean time of adoption is the arithmetical average of all the individual elapsed times to adoption, and provides a reference point with which to compare any particular individual's time of adoption. However the difference between the mean time and the individual time only indicates how far ahead or behind the average the individual was, and not how many other individuals were also equally far ahead or behind. In order to assess the latter a measure of the dispersion of individuals around the mean is needed, and the standard deviation is one such measure. In a new product context the measurement of an individual's innovativeness can be defined as follows.
