A Practical Measure of Offence Seriousness: Sentence Severity , continued
Of course, such arguments about the relative merits of one scale over another, although possibly pointing to salient features of each scale, are apt to be specious. In the last analysis, the judgement about the relative merits of two measures of the same thing will be made by the user. It would seem appropriate, therefore, to provide the potential user of a scale of offence seriousness with the basic data on which he or she can exercise appropriate judgement.
In order to permit meaningful addition of values for various kinds of offenses, a scale of offence seriousness must be at least at the interval level of scaling. If a scale is distributed in equal units of measurement, it should be possible to identify the orderly arithmetic progression of the various elements, and the equivalence of proportions among pairs of elements across the range of the scale. These requirements form the essential basis for Stevens’ (1957) Power Law, which was the basis on which Sellin and Wolfgang (1964) and Wolfgang, et al. (1985) determined their offence seriousness values. Actually, the Power Law requires that a physical scale form part of the equation. It will be recalled that, for want of an actual physical scale of offence seriousness, Sellin and Wolfgang (1964) created a conceptual physical scale in referring to the social harm consequences of crime. In evaluating the ratios between offence types, therefore, this implicit “physical” scale needs to be kept in mind, as well as the idea that one aspect of the social harm consequences of an offence may be represented by the duration of the protection of society required, i.e., the length of the sentence imposed.