The main goal of this paper is to describe a general approach to the problem of understanding linguistic phenomena, as they appear in lexical semantics, through the analysis of large scale resources, while exploiting these results to improve the quality of the resources themselves. The main contributions are: the approach itself, a formal quantitative measure of language diversity; a set of formal quantitative measures of resource incompleteness and a large scale resource, called the Universal Knowledge Core (UKC) built following the methodology proposed. As a concrete example of an application, we provide an algorithm for distinguishing polysemes from homonyms, as stored in the UKC.