Statistical linguistics is nowadays generally recognized as the one of the major branches of linguistics . Statistical inquiries have considerable importance because of their relevance to certain problems of communication engineering & information theory . Statistical approach proved essential in the selection of vocabulary items of a foreign language for teaching purposes . Very few people know more than 10% of the words in their mother tongue . It follows that if we do not wish to waste time on committing to memorize vocabulary items which are never likely to be useful to the learner we have to select only lexical units that are commonly used by a native speaker .

Out of approximately 500 000 words listed in Oxford English dictionary the active vocabulary of an educated Englishman comprises no more than 30 000 words & of these 4 000 - 5 000 are presumed to be amplisufficient for the daily needs of an average member of the English speech community. Thus , it is evident that the problem of selection of teaching vocabulary is of vital importance . Statistical techniques have been successfully applied in the analysis of various linguistic phenomena . Different structural types of words , affixes , the vocabularies of great writers & poets & even in the study of some problems of Historical Lexicology .

Statistical regularities can be observed only if the phenomena under analysis are sufficiently numerous . Thus , the first requirement of any statistic investigation is the size of the sample . It is known that comparatively small group of words makes up the bulk of any text . It was found that approximately 1300 – 1500 most frequent words make up 85% of all words occurring in the text . If however we analyze a sample of 60 words it is hard to predict the number of occurrences of most frequent words .

e. g. If we take the word “room” we can find some meanings of the word : 1) “room”- denoting “space” as in “take less room , not enough room to do smth.”; 2) part of a house as in “sitting-room” ; 3) used in plural = lodgings as in “to get rooms”. Statistical analysis shows that most frequently the word is used in its second meaning – 83% of all occurrences of the word in different texts , 12% of all takes its first meaning – “space”, & only 2% takes the third meaning of the word .

Immediate constituents analysis .

The theory of Immediate Constituents was originally elaborated as an attempt to determine the ways in which lexical units are relevantly related to one another . It was discovered that combinations of units are usually structured into hierarchial sets of binary constructions .

e. g. In the word-group “ a black dress in severe style “ we do not relate the indefinite article “a” to adjective “black” , “black” to “dress” , “dress” to “in” , “in” to “severe” , “severe” to “style” .We set up a structure which may be represented as “a black dress” & “in severe style”.

Thus , the fundamental aim of immediate constituents analysis is to segment a set of lexical units into two maximally independent sequences & these maximally independent sequences are called immediate constituents . The further segmentation of immediate constituents results in ultimate constituents , which means that further segmentation is impossible for no meaning can be found .

e. g. The ultimate constituents of the phrase given are “a” ,”black” , “dress” , “ in” , “severe” , “style” .

This method of analysis is extremely fruitful in discovering the derivational structure of words .

Distributional analysis .

Distributional analysis in its various forms is commonly used nowadays. By the term “distribution” we understand the occurrence of a lexical unit relative to another lexical units of the same levels : words to words , morpheme to morphemes . In other words , by this term we understand the position which lexical unit occupies or may occupy in the text or in the flow of speech . It is observed that a certain component of the word-meaning is described when the word is identified distributionally .

e. g. In the sentence

The boy home .

the missing word is easily identified as a verb . It may be “came , ran , went , goes” , but not as an adverb or a noun , or an adjective .

Thus , we see that the component of meaning that is distributionally identified is actually the part-of-speech meaning . It is also observed that in a number of cases words have different lexical meanings in different distributional patterns .

e. g. The verb “to treat” has different lexical meanings in “to treat smbd kindly” & “to treat smbd to ice-cream” .

The interdependence of distribution & meaning can be also observed at the level of word-groups .

e. g. It is only the distribution of completely identical lexical units but arranged on the reverse that differentiates the meaning – water tap & tap water .

Transformational analysis .

Transformational analysis in lexicological investigations may be defined as repatterning ( representing , reorganization ) of various distributional structures in order to discover difference or sameness of meaning of practically identical distributional patterns . As distributional patterns are in a number of cases polysemantic transformational procedures are of help not only in the analysis of semantic sameness / difference of the lexical units but also in the analysis of the factors that account for their polysemy . Word-groups of identical distributional structure when repatterned show that the semantic relations between words & consequently the meaning may be different .e. g. A pattern “possessive pronoun ”+”noun”(his car , his failure , his arrest, his kindness ). According to transformational analysis the meaning of each word-group may be represented as : he has a car , he failed , he was arrested , he is kind. In each of the cases different meaning is revealed : possession , action , passive action , quality .The rules of transformation are rather strict & shouldn’t be identified with paraphrasing in the usual sense of the term .There are many restrictions both on syntactic & lexical levels . These are :

I. Permutation – the repatterning on condition that the basic subordinative relationships between words & word-stems of the lexical units are not changed .e. g. “His work is excellent “ may be transformed into “ his excellent work , the excellence of his work , he works excellently “.In the example given the relationships between lexical units & the stems of the notional words are essentially the same .