The third component in language variation is in the understanding that language variation itself will never be fully completed. This means that due to the myriad of factors that come into play when studying one area's languages, its dialects and variations of the core language there will never be one set of directives that will be able to remain the same when studying another area's languages.
Each area of study is different just as each child's comprehension of their language will be different than that of their peers. If we look at each child as a variation, then it is important to look at each variation as a possible language variation in itself.
There are currently more studies being conducted on the essence and components of language variation. An excellent series of papers from the United Kingdom's Cambridge University's Linguistics Department can be read online in .PDF format at Paper Li.2 Language Variation.
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