Phonological typology and naturalness

A widely invoked criterion in deciding between analyses of a language is whether the rules of one analysis are more natural, usually judged in terms of whether the rules occur frequently across languages. As a prerequisite to explaining why some processes are common, uncommon, or even unattested, you need an idea of what these common patterns are, and providing such survey information is the domain of typology. While only a very small fraction of the roughly 7,000 languages spoken in the world have been studied in a way that yields useful information for phonological typology, crosslinguistic studies have revealed many recurrent patterns, which form the basis for theorizing about the reason for these patterns.