A '''vulnerability index''' is a composite of [[Index|indices]], also referred to as integrated indices, which are quantitative indicators similar to [[scalesscale (social sciences)|scale]]{{dn|date=October 2011}}s, which, when entered into a formula, deliver a single numerical result which can be used for triage (prioritization) and policy analysis. Through their use, ““diverse issues can be combined into a standardised framework…making comparisons possible”.<ref>http://www.geog.ox.ac.uk/news/events/ccamts/appendix06.pdf</ref> For instance, variable from physical science can be combined with social, medical and even psychological variables to evaluate potential complications in disaster planning contexts. The development of vulnerability indexes as a policy planning tool occurred at the instance of the United Nations Environmental Program and one of the participants in the early task forces has also conducted secondary research documenting the evolution of the analytic tool through various stages.<ref>http://www.unep.org/ourplanet/imgversn/103/17_mea2.htm</ref> The term and methodology then proceeded to promulgate <ref>http://www.macchomeless.org/pdf/ResultsFactSheet-Omaha.pdf</ref> through medical literature and social work as discussed by Dr. James O'Connell of the Boston Healthcare for the Homeless.<ref>http://www.commonground.org/?page_id=789</ref><ref>O'Connor, James| Unpublished public forum presentation|University of Santa Barbara|Santa Barbara, California 2011</ref>
== Basic methodology ==
The basic methodology of constructing a vulnerability index is described by Briguglio<ref>http://www.unep.org/ourplanet/imgversn/103/17_mea2.htm</ref> and is quite simple and not without antecedents. Different relative importance is assigned to the different factors (weighting). A cumulative [[score]] is then generated. Through application of variable scenarios decision trees can be developed reflecting alternative policy options.Much of the original research has been evaluated by Lino Briguglio and presenters at Oxford, providing a body of secondary source material which is known primarily to workers in specialized areas of development.
