Talk:Tf–idf

message: Why title of the article is in lower case? Why not "TF-IDF"? --ajvol 15:29, 25 November 2006 (UTC)
replies: text:  In other papers I see the sign of multiplication TF*IDF, not minus. See, e.g. S. Robertson, Understanding inverse document frequency: on theoretical arguments for IDF. Journal of Documentation 60, 503-520, 2004.  What do you think about renaming the article? --AKA MBG (talk) 14:18, 7 March 2008 (UTC)
replies: text: By far, the most common representation in the literature is lowercase with an asterisk or similar multiplication symbol. I agree that this article should be renamed if the Wikimedia allows * in article names. 13:20, 26 June 2009 (UTC)
thread_title:  Naming of the statistic (and this article) 

message: Why is TF-IDF spelled with an en dash in this article? zachaysan (parley) 21:29, 27 September 2020 (UTC)
thread_title:  Use of En Dash 

message: You could extract the most relevant terms from a version of a page of Wikipedia, perhaps this very one, as an example. --84.20.17.84 15:20, 15 March 2007 (UTC)
replies: text: This is a good idea.  I'll do it tomorrow.  —Preceding unsigned comment added by 67.170.95.139 (talk) 07:10, 9 December 2008 (UTC)

text: I'd warn against using a Wikipedia article, since they change over time, which impedes reproducibility; it's better to choose a static document, such as a public domain text. If it explicitly references Wikipedia, it also runs afoul of Wikipedia:Avoid self-reference. Dcoetzee 09:29, 9 December 2008 (UTC)
thread_title:  Example 

message: * I think we can also use tf-idf in text data clustering. I would like to know any Java source code on unstructured text data clustering based on tf-idf?  —Preceding unsigned comment added by 125.53.215.245 (talk) 03:09, 12 September 2007 (UTC)
thread_title:  Text Data Clustering 

message: The frequency of the terms isn't usually normalized by dividing it for the total length of each document. Instead, normalization is done by dividing for the frequency of the most used term in the document (as outlined in http://www.miislita.com/term-vector/term-vector-4.html).  —Preceding unsigned comment added by 151.53.133.126 (talk) 18:59, 29 February 2008 (UTC)
replies: text: I've removed the normalization from the definition of tf following several discussions on mailing lists about tf implementations. The (unsourced!) variant previously described has sown a lot of confusion on the 'net. Qwertyus (talk) 12:46, 29 June 2011 (UTC)

text: I have edited the section to provide one particular formula, but have tried to emphasize that the given formula is not necessarily the definitive version.  Hope this was helpful. 72.195.132.12 (talk) 05:03, 17 August 2012 (UTC)
thread_title:  Normalized frequencies 

message: Can someone please specify the logarithm bases correctly? Is that binary or base 10 log?  —Preceding unsigned comment added by Godji (talk • contribs) 12:03, 20 March 2008 (UTC)
replies: text: it doesn't matter as long as they are all the same in your calculations 24.222.83.249 (talk) 23:42, 1 June 2008 (UTC)

text: Remember that \log_a(x) = \log_b(x) / \log_b(a).  This means that converting between two logarithm bases is just multiplication by a constant. 72.195.132.12 (talk) 04:03, 17 August 2012 (UTC)
thread_title:  Logarithms 

message: It maybe the issue of the Information Retrieval community as whole, but the definition of IDF is an intellectual insult for anybody with a reasonable natural sciences background. Saying that IDF (Inverse Document Frequency) = log ( 1 / document frequency ) should be prohibited! Maybe the place to fix this is wikipedia, since we can't fix IR textbooks and papers...  —Preceding unsigned comment added by 194.58.241.106 (talk) 19:50, 14 June 2008 (UTC)
replies: text: That would be original research, which is not permitted. We should describe IDF as it is defined and used in the field of IR. If someone in the natural sciences has published something about why this is a poor choice for a formula, it could probably be given a couple sentences somewhere. Dcoetzee 09:41, 9 December 2008 (UTC)

text: So what if someone is insulted.  The job of the wikipedia is to convey information...if you feel insulted about something, go ask your mother for a hug.  —Preceding unsigned comment added by 206.169.37.100 (talk) 20:16, 13 May 2009 (UTC)

text: If there is a significant difference in the way the term is used across disciplines, a disambiguation page may be in order. That information may not need to be included in this article, however. Universaladdress (talk) 06:14, 12 August 2012 (UTC)
thread_title:  Idf definition 

message: The index notation here is difficult to understand quickly because you use i for word and j for document.  It would be much easier to read and grok if you used w, w', w" for words, and d, d', d" for documents.  —Preceding unsigned comment added by 206.169.37.100 (talk) 20:12, 13 May 2009 (UTC)
replies: text: \mathrm{(tf\mbox{-}idf)_{i,j}} = \mathrm{tf_{i,j}} \times  \mathrm{idf_{i}}   —Preceding unsigned comment added by 137.250.39.119 (talk) 12:13, 17 June 2009 (UTC)
thread_title:  Notation very confusing 

message: In the example the term frequency should the absolute count of term in the document, and shouldn't be divided by all term counts in the dictionary
*Detailed discussion about this question above on the talk page. Expert help has been sought to clarify the article. Universaladdress (talk) 15:46, 29 April 2012 (UTC)
thread_title:  Example is incorrect 

message: Concerns the topic of this article.  Appears after "When the length of the words in a document goes to".  I'm deleting it; hopefully s.o. here can fix.  — kwami (talk) 23:13, 17 January 2014 (UTC)
replies: text: Why are you reporting this here, instead of at Talk:Web mining? QVVERTYVS (hm?) 23:24, 17 January 2014 (UTC)
thread_title:  corrupted text at [[Web mining]] 

message: What does the "K" stand for in "Double Normalization K"?  — Preceding unsigned comment added by 195.159.43.226 (talk) 15:06, 15 September 2015 (UTC)
replies: text: Looks like it's just a nameless constant that somebody decided to call . I.e., it doesn't stand for anything. QVVERTYVS (hm?) 15:14, 15 September 2015 (UTC)
thread_title:  Double Normalization K 

message: This table is confusing. Scheme 3 is identical for document and query term, which does not make sense. --zeno (talk) 12:42, 13 December 2018 (UTC)
replies: text: I agree with above comment for multiple points. First, column headers make references to unexplained terms: what is "document term weight", is it equivalent to the "idf weight" presented in the previous table (same thing apply for next column). Second, weights presented in columns do not reflect the ones presented in variation tables, making them difficult to understand which component (tf or idf) they relates to. Then, weighting scheme column brings few information, just numbering the schemes. Do these scheme actually have a name ? Are they referenced in some published article (if yes, maybe a citation should be added). Finally, the layout does not follow the one of the two other variants table (table title, left aligned), making it unclear if it is part of the tf*idf "standard" or some variations of it. AlexisBRENON (talk) 10:14, 21 November 2022 (UTC)
thread_title:  Recommended tf–idf weighting schemes 

message: In the middle Formula appears a W. Probably this should be a T?!--Tobias.rostock (talk) 12:47, 26 November 2019 (UTC)
thread_title:  Typo in Link with Information Theory 

message: Why did you change the tense in the lede section to past tense in this edit? I can't believe that tf-idf is not used any more... --Wrongfilter (talk) 10:36, 9 February 2024 (UTC)
thread_title:  Past tense in introduction