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Corpus analysis (2)

Corpus analysis (2). Corpus Linguistics Richard Xiao lancsxiaoz@googlemail.com. Outline of the session. Lecture Keyword Reference corpus Key keyword Practical WST keyword AntConc keyword Wmatrix keyword / key concept Extra: keyword analysis with CQPweb. What is a keyword?.

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Corpus analysis (2)

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  1. Corpus analysis (2) Corpus Linguistics Richard Xiao lancsxiaoz@googlemail.com

  2. Outline of the session • Lecture • Keyword • Reference corpus • Key keyword • Practical • WST keyword • AntConc keyword • Wmatrix keyword / key concept • Extra: keyword analysis with CQPweb

  3. What is a keyword? • Keywords are those words whose frequency is exceptionally high (positive keywords) or low (negative keywords) in comparison with a reference corpus • Keywords usually refer to positive keywords • But negative keywords are equally interesting (see Xiao and McEnery 2005) • They appear at the very end of your listing, in a different colour in WordSmith • They are omitted automatically from a keywords database for key keyword analysis and a keyword plot

  4. Why keyword analysis? • Indicating the ‘aboutness’ (Scott 1999) of a particular text or corpus • Contents analysis, discourse analysis • Also revealing the salient features which are functionally related to a particular genre (Xiao and McEnery 2005) • Genre analysis, stylistic analysis

  5. How to do keyword analysis • Make a wordlist of the target corpus • Locate or make a word list of a reference corpus • Scott (2005) “In search of a bad reference corpus” • http://www.methodsnetwork.ac.uk/redist/pdf/es1_05scott.pdf • The reference corpus is usually larger than the target corpus • The appropriateness of a reference corpus depends on your research questions! • Compare the frequency of each item in the two wordlists to extract keywords – done automatically • Analyse and interpret keywords – you will do it!

  6. Keywords in the party speeches • Target corpus – just one text • David Cameron's speech at the Conservative conference (10 October 2012, Manchester) • http://www.bbc.co.uk/news/uk-politics-15189614 • Local copy available (David_speech Unicode text) - download and unzip the file into a file folder: www.fass.lancs.ac.uk/projects/corpus/data/workshop3texts.zip • Reference corpus • The 100-million-word BNC: download and unzip (local copy available) www.lexically.net/downloads/version4/BNC_World.zip • Tool • WST Keyword

  7. Wordlist of David’s speech

  8. Creating keyword list

  9. Keyword extraction in progress Warning: It can take time if you have loaded two large wordlists

  10. Keywords in David’s speech What do these keywords tell us? Negative keyword

  11. Keyword: Plot view

  12. What companies do keywords keep?

  13. Why “marriage”?

  14. Key clusters Similar to word clusters, but only keywords are used.

  15. Key keywords • A key keyword is one which is "key" in more than one of a number of related texts • The more texts it is "key" in, the more "key key" it is • Can avoid extracting keywords which are unusually frequent in only a small number of files • Can be created automatically and as simple to extract as you do for keywords • n.b. Negative keywords are omitted automatically from a key keyword list

  16. Making a batch wordlist Specify a folder where you can write

  17. Batch making keyword lists

  18. Batch making keyword lists Specify a folder where you can write

  19. Making a KW database

  20. Key keywords An "associate" is a keyword that appears in the same text key coverage of the corpus

  21. Keyword in AntConc target corpus reference corpus

  22. Keyword in AntConc Key words in David's speech (in relation to Ed's speech)

  23. Wmatrix: Keywords and key concepts • POS and semantic tagging • Keyword / key concept analysis in Cameron’s speech in comparison with Miliband’s speech • Copy and paste the speeches into two separate text files • http://www.bbc.co.uk/news/uk-politics-15189614 • http://www.labour.org.uk/ed-milibands-speech-to-labour-party-conference • Save the two texts as David_speech.txt and Ed_speech.txt www.fass.lancs.ac.uk/projects/corpus/data/workshop3texts.zip

  24. Wmatrix: Keywords and key concepts • Login with your account using zhejiangxx account • http://ucrel.lancs.ac.uk/wmatrix3.html

  25. Tagging Wizard

  26. Tagging in progress

  27. Tagging result

  28. Labour frequency list

  29. KWIC concordance

  30. “My folders” Upload and tag Ed’s speech …and click on “My folders” Warning: Your folder view may look different!

  31. Open David_speech folder and select Ed_speech in “Keyword compared to” dropdown box

  32. Keyword list to download!

  33. Keyword cloud – even more interesting!

  34. David’s key concepts(“Key concepts compared to”)

  35. Keyword analysis in online corpora • Using Lancaster’s CQPweb to compare British English (LOB+FLOB) and American English (Brown + Frown) • Login CQPweb • http://cqpweb.lancs.ac.uk • Similar analysis can be done at BSFU’s CQPweb corpus hub (different corpora) • http://124.193.83.252/cqp/ • Account: ID=pass=test

  36. Creating subcorpora

  37. Creating subcorpus BrE

  38. Creating subcorpus AmE

  39. Making wordlists

  40. Wordlist available now

  41. Computing keywords You can make adjustments to the statistical measure, cut-off point, and minimum frequency according your research purposes.

  42. Keywords in BrE and AmE

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