Kocabas, IlkerDincer, Bekir TanerKaraoglan, Bahar2019-10-272019-10-2720111300-06321303-62031300-06321303-6203https://doi.org/10.3906/elk-1003-448https://hdl.handle.net/11454/44865In this study, we show how Luhn's claim about the degree of importance of a word in a document can be related to information retrieval. His basic idea is transformed into z -scores as the weights of terms for the purpose of modeling terra frequency (If) within documents. The Luhn-based models represented in this paper are considered as the TF component of proposed TF x IDF weighing schemes. Moreover, the final term weighting functions appropriate for the TF x IDF weighting scheme are applied to TREC-6, -7, and -8 databases. The experimental results show relevance to Luhn's claim by having high mean average precision (MAP) for the terms with frequencies around the mean frequency of terms within a document. On the other hand, the weighting, which significantly discriminates the importance between low/high frequencies and medium frequencies, degrades the retrieval performance. Therefore, any weighting scheme (TF) that is directly proportional to If has a probability of high retrieval performance, if this can optimally indicate the difference of the importance regarding tf values and also optimally eliminate the terms that have high frequencies.en10.3906/elk-1003-448info:eu-repo/semantics/closedAccessLuhninformation retrievalterm weightingindexingArticle1969931004WOS:000295497900013Q3Q4