Guideline 6.3-- Cardinal Measure of Preference. The method of aggregating
performance measures should produce a cardinal measure of preference rather than
an ordinal measure of preference, unless it can clearly be demonstrated that the use
of an ordinal measure will not alter or otherwise invalidate the results.
Discussion. Cardinal measures distinguish the benefits on an absolute scale,
specifying the amount by which a given benefit differs from another. Ordinal
measures, however, only distinguish more benefit from less, and allow items to be
ranked, but they do not specify the amount by which something is preferred. For
example, if an aggregated value of " "is assigned to one activity and a value of " "is
assigned to another activity, the second activity is preferred to the first. However, the
conclusion that the second activity produces twice the benefit of the first can only be
drawn if the aggregate measure is a cardinal one.
9.7 Guidelines Primarily Associated with Defensibility.
Guideline 7.1-- Qualification of Participants. Participants in RBP applications should
have demonstrated education, experience, or training to properly perform their
Discussion. There is little value in completing a prioritization only to have the results
challenged because of unqualified participants. It is important that the participants
have the needed expertise in developing the model, eliciting values, defining decision
objectives, scoring activities, estimating costs, and providing risk estimates. To
minimize challenges of the prioritization results, the qualification of all participants
should be identified and documented.
Guideline 7.2-- Level of Detail. Proposed activities should be clearly defined. The
work to be conducted and the expected consequences of that work should be
described and documented. A sample checklist is presented in Table III.
TABLE III. Checklist for Characterizing Decision Options
Statement of Work
Discussion. It is impossible to meaningfully estimate the costs and benefits of
ill-defined activities. Thus, the work to be conducted should be clearly specified prior
to being evaluated in an RBP process. Documentation should include a clear, concise
description of the scope of work, necessary resource requirements, motivations for
conducting the activity, and impacts that the activity is expected to produce.