Discovery of knowledge using text mining techniques applied to textual documents of brazilian police investigation

Abstract

The aim of this study is to analyze how text mining techniques applied to textual documents of Brazilian police investigation can promote knowledge dis-covery. The research collected documents from the police investigation and submitted them to the text mining process. The study used the techniques of case folding, tokenization, custom stopwords, bag of words and TF-IDF in order to extract results in n-grams. The results were presented with word clouds. In the research, k-means were used to cluster the sets of trigrams, identifying in each clusters the most rep-resentative terms of the clusters. The use of text mining techniques on these documents was intended to extract non-trivial knowledge. The techniques of text mining, or discovery of knowledge in a textual database, have the purpose of discovering unobserv-able patterns when analyzed by human manipulation of large volumes of documents. The results found fa-vored the discovery of knowledge in the identification of entities and connections, as well as thematic cat-egories of the investigation.