Editing Comparative linguistics (section)

==History==
{{see also|Comparative method#Origin and development}}
The earliest method of this type was the comparative method, which was developed over many years, culminating in the nineteenth century. This uses a long word list and detailed study. However, it has been criticized for example as subjective, informal, and lacking testability.<ref>See for example ''Language Classification by Numbers'' by April McMahon and Robert McMahon</ref> The comparative method uses information from two or more languages and allows reconstruction of the ancestral language. The method of [[internal reconstruction]] uses only a single language, with comparison of word variants, to perform the same function. Internal reconstruction is more resistant to interference but usually has a limited available base of utilizable words and is able to reconstruct only certain changes (those that have left traces as morphophonological variations).

In the twentieth century an alternative method, [[lexicostatistics]], was developed, which is mainly associated with [[Morris Swadesh]] but is based on earlier work. This uses a short word list of basic vocabulary in the various languages for comparisons. Swadesh used 100 (earlier 200) items that are assumed to be cognate (on the basis of phonetic similarity) in the languages being compared, though other lists have also been used. Distance measures are derived by examination of language pairs but such methods reduce the information. An outgrowth of lexicostatistics is [[glottochronology]], initially developed in the 1950s, which proposed a mathematical formula for establishing the date when two languages separated, based on percentage of a core vocabulary of culturally independent words. In its simplest form a constant rate of change is assumed, though later versions allow variance but still fail to achieve reliability. Glottochronology has met with mounting scepticism, and is seldom applied today. Dating estimates can now be generated by computerised methods that have fewer restrictions, calculating rates from the data. However, no mathematical means of producing proto-language split-times on the basis of lexical retention has been proven reliable.

Another controversial method, developed by [[Joseph Greenberg]], is [[mass comparison]].<ref>[[Lyle Campbell|Campbell, Lyle]] (2004). ''Historical Linguistics: An Introduction'' (2nd ed.). Cambridge: The MIT Press</ref> The method, which disavows any ability to date developments, aims simply to show which languages are more and less close to each other. Greenberg suggested that the method is useful for preliminary grouping of languages known to be related as a first step toward more in-depth comparative analysis.<ref>Greenberg, J. H. (2001). "The methods and purposes of linguistic genetic classification". ''Language and Linguistics'' 2: 111–135.</ref> However, since mass comparison eschews the establishment of regular changes, it is flatly rejected by the majority of historical linguists.<ref>Ringe, Don. (1993). "A reply to Professor Greenberg". ''Proceedings of the American Philosophical Society'' 137, 1:91–109. {{doi|10.1007/s101209900033}}. {{JSTOR|986947}}</ref>

Recently, computerised statistical hypothesis testing methods have been developed which are related to both the [[comparative method]] and [[lexicostatistics]]. Character based methods are similar to the former and distanced based methods are similar to the latter (see [[Quantitative comparative linguistics]]). The characters used can be morphological or grammatical as well as lexical.<ref>e.g. Greenhill, S. J., Q. D. Atkinson, A. Meade, and R. D. Gray. (2010). "[http://simon.net.nz/files/2010/04/Greenhill_et_al2010-preprint.pdf The shape and tempo of language evolution] {{Webarchive|url=https://web.archive.org/web/20180128134551/http://simon.net.nz/files/2010/04/Greenhill_et_al2010-preprint.pdf |date=28 January 2018 }}". ''Proceedings of the Royal Society B: Biological Sciences'' 277, no. 1693: 2443–50. {{doi|10.1098/rspb.2010.0051}}. {{JSTOR|25706475}}.</ref> Since the mid-1990s these more sophisticated tree- and network-based [[phylogenetic]] methods have been used to investigate the relationships between languages and to determine approximate dates for proto-languages. These are considered by many to show promise but are not wholly accepted by traditionalists.<ref>See for example the criticisms of Gray and Atkinson's work in {{cite web |last=Poser |first=Bill |title=Dating Indo-European |website=Language Log |date=10 December 2003 |url=http://itre.cis.upenn.edu/~myl/languagelog/archives/000208.html |access-date=1 June 2017 |archive-date=19 June 2017 |archive-url=https://web.archive.org/web/20170619221556/http://itre.cis.upenn.edu/~myl/languagelog/archives/000208.html |url-status=live }}</ref> However, they are not intended to replace older methods but to supplement them.<ref>Greenhill, S. J., and R. D. Gray. 2009. "[http://simon.net.nz/files/2009/09/Greenhill_and_Gray2009.pdf Austronesian language phylogenies: Myths and misconceptions about Bayesian computational methods] {{Webarchive|url=https://web.archive.org/web/20180128134559/http://simon.net.nz/files/2009/09/Greenhill_and_Gray2009.pdf |date=28 January 2018 }}". In ''Austronesian historical linguistics and culture history: a festschrift for Robert Blust'', ed. K. A. Adelaar and A. Pawley, 375–397. Canberra: Pacific Linguistics.</ref> Such statistical methods cannot be used to derive the features of a proto-language, apart from the fact of the existence of shared items of the compared vocabulary. These approaches have been challenged for their methodological problems, since without a reconstruction or at least a detailed list of phonological correspondences there can be no demonstration that two words in different languages are cognate.{{Citation needed|date=August 2007}}