Topic Word Generation Method and System

• US 20110231411A1
• Filed: 11/07/2008
• Published: 09/22/2011
• Est. Priority Date: 08/08/2008
• Status: Active Grant

• Current Assignee: Quillsoft Ltd.
• Original Assignee: Holland Bloorview Kids Rehabilitation Hospital
• Inventors: Li, Dan, Nantais, Tom, Shein, Fraser
• Granted Patent: US 8,335,787 B2
• Time in Patent Office: Days
• US Class Current: 707/749
• CPC Class Codes: G06F 16/355 Class or cluster creation or modification

Abstract

A method of, and system for, extracting topic words from a collection of documents across multiple and potentially very large number of domains. Documents are selected and ranked based on similarity with at least one seed word, which defines a topic. Seed words may be entered directly by a user or provided by another application. Keywords are extracted from documents determined to be a sufficiently good match to the topic and may be displayed to the user or used as input into word prediction or word analysis and display software. Documents are determined to be a sufficiently good match to the topic using an iterative algorithm starting with the best match and selecting documents containing keywords sufficiently similar to the previously selected documents.

Claims

1. A method of generating topic words from at least one seed word and a collection of documents comprising the steps of:

a. identifying keywords in each document that are indicative of the topic of the document;

b. evaluating the relevance of the keywords from each of the documents to the at least one seed word;

c. identifying at least one key topic document that is relevant to the at least one seed word;

d. selecting a subset of the documents, referred to as topic documents, by an iterative process starting with the selection of the at least one key topic document and then selecting other documents if their keywords are sufficiently similar to the keywords contained in the previously selected topic documents; and

e. extracting a set of topic words from the topic documents.

2. The method of claim 1 wherein each document comprises an index, and the evaluation step comprises producing a sorted list of document indices that include the at least one seed word based on relevance to the at least one seed word, and to identify at least one key topic document index that is highly relevant to at least one seed word.

3. The method of claim 2 wherein the relevance of a document index is evaluated by comparison of the at least one seed word to the title of each document and keywords contained within each document index.

5. The method of claim 1 wherein in the step of identifying keywords, words contained in a pre-defined dictionary are excluded from consideration as keywords.

6. The method of claim 1 wherein in the step of identifying keywords, words that serve structural purposes are excluded from consideration as keywords.

7. The method of claim 1 wherein in the step of evaluating the relevance of each of the documents, documents determined to be unlikely to pertain to a single topic are eliminated prior to identifying the at least one key topic document.

10. The method of claim 1 wherein the relevance of a document to the at least one seed word is determined based on the frequency of occurrence of the seed words in the title of the document and within the document.

11. The method of claim 1 wherein the at least one key topic document is chosen to be the document that is most relevant to the at least one seed word if that document is sufficiently relevant to the at least one seed word and otherwise all documents with at least a pre-defined level of relevance to the at least one seed word are chosen to be key topic documents.

12. The method of claim 1 wherein the topic documents include the at least one key topic document and the other topic documents are selected by an algorithm that considers each document, one at a time, in declining order of relevance to the at least one seed word, and selects a document as a topic document if it contains at least a predefined percentage of keywords that occur as keywords of the previously selected topic documents.

13. The method of claim 1 wherein at least one document in the collection of documents is obtained from a specified source.

19. The method of claim 1 wherein the extracted topic words are further processed to eliminate redundant topic words having common morphological roots.

21. The method of claim 1, wherein the collection of documents is pre-processed such that each document in the collection of documents shares a commonality.

48. A memory having recorded thereon statements and instructions for execution by a computer to carry out the method of claim 1.

49. A method comprising transmitting over a communications medium computer-executable instructions for causing a computer system programmed thereby to perform the method of claim 1.

51. The method of claim 1 wherein the at least one seed word is obtained by analyzing user-entered text.

4. (canceled)

8-9. -9. (canceled)

14-18. -18. (canceled)

20. (canceled)

22-23. -23. (canceled)

24. A system for extracting topic words from documents based on at least one seed word comprising a series of modules including:

a. a keyword identification module for identifying keywords in each document that are indicative of the topic of the document;

b. an evaluation module for evaluating the relevance of each of the documents to the at least one seed word;

c. a key topic document identification module for identifying at least one key topic document that is relevant to the at least one seed word;

d. a selection module for selecting a subset of the documents, referred to as topic documents, by an iterative process starting with the at least one key topic document and then selecting other documents if their keywords are sufficiently similar to the keywords contained in the previously selected topic documents; and

e. an extraction module for extracting a set of topic words from the topic documents.

25. The system of claim 24 wherein each document comprises an index, and the evaluation module produces a sorted list of document indices that include the at least one seed word based on relevance to the at least one seed word, and identifies at least one key topic document index that is highly relevant to at least one seed word.

26. The system of claim 25 wherein the relevance of a document index is evaluated by comparison of the at least one seed word to the title of each document and keywords contained within each document index.

28. The system of claim 24 wherein in the step of identifying keywords, the keyword identification module excludes words contained in a pre-defined dictionary from consideration.

29. The system of claim 24 wherein in the step of identifying keywords, the keyword identification module excludes words that serve structural purposes.

30. The system of claim 24 wherein the system further comprises a filtering module for eliminating documents determined to be unlikely to pertain to a single topic prior to the execution of the keyword identification module.

33. The system of claim 24 wherein the relevance of a document to the at least one seed word is determined by the evaluation module based on the frequency of occurrence of the seed words in the title of the document and within the document.

34. The system of claim 24 wherein the at least one key topic document is chosen by the key topic document identification module to be the document that is most relevant to the at least one seed word if that document is sufficiently relevant to the at least one seed word and otherwise all documents with at least a pre-defined level of relevance to the at least one seed word are chosen to be key topic documents.

35. The system of claim 24 wherein the topic documents are selected by the selection module to include the at least one key topic document and the other topic documents are selected by an algorithm that considers each document, one at a time, in declining order of relevance to the at least one seed word, and selects a document as a topic document if it contains at least a predefined percentage of keywords that occur as keywords of the previously selected topic documents.

36. The system of claim 24 wherein at least one document in the collection of documents is obtained from a specified source.

42. The system of claim 24 wherein the extracted topic words are further processed to eliminate redundant topic words having common morphological roots.

44. The system of claim 24, wherein the collection of documents is pre-processed such that each document in the collection of documents shares a commonality.

52. The system of claim 24 wherein the at least one seed word is obtained by analyzing user-entered text.

27. (canceled)

31-32. -32. (canceled)

37-41. -41. (canceled)

43. (canceled)

45-47. -47. (canceled)

50. (canceled)