Selleks et erinevaid kriteeriumeid üksteisega võrreldavateks muuta, tuleb järgida mõõtude sünteesi reegleid ning luua protseduurid, kuidas välja selgitada erinevate mõjurite osakaalu. Seda nimetatakse multikriteeriumiliseks hindamiseks (ingl multicriteria evaluation, MCE).
As has been shown by Carver (1991) and others, a systematic approach to site selection is provided by the techniques of multi-criteria evaluation (MCE) and these techniques can be incorporated within GIS.
The purpose of MCE is to help decision-makers distinguish between several possible options, where the preference for each of the options may depend upon several factors, each of which might be regarded as having different levels of importance by different members of the community.
