Editing Joseph Greenberg (section)

===Mass comparison===
{{main|Mass comparison}}

Greenberg rejected the opinion, prevalent among linguists since the mid-20th century, that [[comparative method|comparative reconstruction]] was the only method to discover relationships between languages. He argued that genetic classification is methodologically prior to comparative reconstruction, or the first stage of it: one cannot engage in the comparative reconstruction of languages until one knows which languages to compare (1957:44).

He also criticized the prevalent opinion that comprehensive comparisons of two languages at a time (which commonly take years to perform) could establish language families of any size. He argued that, even for 8 languages, there are already [[Bell number|4,140 ways]] to classify them into distinct families, while for 25 languages there are 4,638,590,332,229,999,353 ways (1957:44). For comparison, the [[Niger–Congo languages|Niger–Congo]] family is said to have some 1,500 languages. He thought language families of any size needed to be established by some scholastic means other than bilateral comparison. The theory of mass comparison is an attempt to demonstrate such means.

Greenberg argued for the virtues of breadth over depth. He advocated restricting the amount of material to be compared (to basic vocabulary, morphology, and known paths of sound change) and increasing the number of languages to be compared to all the languages in a given area. This would make it possible to compare numerous languages reliably. At the same time, the process would provide a check on accidental resemblances through the sheer number of languages under review. The mathematical probability that resemblances are accidental decreases strongly with the number of languages concerned (1957:39).

Greenberg used the premise that mass "borrowing" of basic vocabulary is unknown. He argued that borrowing, when it occurs, is concentrated in cultural vocabulary and clusters "in certain semantic areas", making it easy to detect (1957:39). With the goal of determining broad patterns of relationship, the idea was not to get every word right but to detect patterns. From the beginning with his theory of mass comparison, Greenberg addressed why chance resemblance and borrowing were not obstacles to its being useful. Despite that, critics consider those phenomena caused difficulties for his theory.

Greenberg first termed his method "mass comparison" in an article of 1954 (reprinted in Greenberg 1955). As of 1987, he replaced the term "mass comparison" with "multilateral comparison", to emphasize its contrast with the bilateral comparisons recommended by linguistics textbooks. He believed that multilateral comparison was not in any way opposed to the comparative method, but is, on the contrary, its necessary first step (Greenberg, 1957:44). According to him, comparative reconstruction should have the status of an explanatory theory for facts already established by language classification (Greenberg, 1957:45).

Most historical linguists (Campbell 2001:45) reject the use of mass comparison as a method for establishing genealogical relationships between languages. Among the most outspoken critics of mass comparison have been [[Lyle Campbell]], [[Donald Ringe]], [[William Poser]], and the late [[Larry Trask|R. Larry Trask]].