A method of detecting a pattern in common in two text files, each comprising an ordered sequence of words, is disclosed. The method includes generating groups of words having the same syntactic function, comprising at least one word from each text file such that each word in a group is synonymous with another word in the same group, associating each word in a text file belonging to a group of words with a tag representative of the group, generating, for each text file, at least one dense set of words satisfying a condition of internal proximity in the text file, determining at least one pattern in common in the two text files, a pattern in common including one or more sets of words sharing the same tag and comprising at least one word from a dense set of words in each text file.