The study of word collocability is one of the main tasks of linguistics. The combinatory ability of language units, collocability, is one of the linguistic syntagmatic laws. This phenomenon is the main object of the phraseology and lexicography. The article deals with set phrases of different types in Russian, Czech and Slovak from the point of view of their quantitative evaluation. Corpus linguistics understand set phrases as statistically determined unities. This approach is the basic point of different automatic ways to extract idioms and collocations. The paper describes experiments which show how text corpora and corpus methods and tools can be used to expand the entries in existing dictionaries and how set phrases could be evaluated quantitatively. It is shown and maintained that corpus linguistics methods and tools allow to create dictionaries of new type which have to include a larger amount of set phrases and collocations than before.