TY - JOUR ID - 21440 TI - Variance-based features for keyword extraction in Persian and English text documents JO - Scientia Iranica JA - SCI LA - en SN - 1026-3098 AU - Veisi, H. AU - Aflaki, N. AU - Parsafard, P. AD - Faculty of New Sciences and Technologies (FNST), University of Tehran, Tehran, Iran AD - Kish International Campus, University of Tehran, Kish, Iran Y1 - 2020 PY - 2020 VL - 27 IS - 3 SP - 1301 EP - 1315 KW - Keyword Extraction KW - Term Frequency KW - Variance KW - Clustering KW - Persian Text Processing DO - 10.24200/sci.2019.50426.1685 N2 - This paper address automatic keyword extraction in Persian and English text documents. Generally, for keyword extraction in a text, a weight is assigned to each token and words having higher weights are selected as the keywords. We have proposed four methods for weighting the words and have compared these methods with five previous weighting techniques. The previous methods used in this paper are term frequency (TF), term frequency inverse document frequency (TF-IDF), variance, discriminative feature selection (DFS), and document length normalization based on unit words (LNU). The proposed weighting methods are based on using variance features and include variance to TF-IDF ratio, variance to TF ratio, the intersection of TF and variance, and the intersection of variance and IDF. For evaluation, the documents are clustered using the extracted keywords as feature vectors, and K-means, expectation maximization (EM), and Ward hierarchical clustering methods. The entropy of the clusters and pre-defined classes of the documents are used as the evaluation metric. For the evaluations, we have collected and labelled Persian documents. Results show that our proposed weighting method, variance to TF ratio, has the best performance for Persian. Also, the best entropy is resulted by variance to TD-IDF ratio for English. UR - https://scientiairanica.sharif.edu/article_21440.html L1 - https://scientiairanica.sharif.edu/article_21440_ad197d880148e31b20fe1bc974c16529.pdf ER -