INFS 427: AUTOMATED INFORMATION RETRIEVAL

Transcription

1 INFS 427: AUTOMATED INFORMATION RETRIEVAL (1 st Semester, 2018/2019) Session 06 AUTOMATED SEARCH PROCESS Lecturer: Mrs. Florence O. Entsua-Mensah, DIS Contact Information: College of Education School of Continuing and Distance Education 2014/ /2017

2 Session Overview Information search is a critical component of the decision process for most information users. The identification and development of information search models has underpinned our understanding of AIR for several decades, offering important guidance on how users interact with their information environments. The Information search model should reflect the processes users undertake in searching an AIRS. Florence O. Entsua-Mensah (Mrs) 3

3 Session Outline The key topics to be covered in the session are: Topic One: The Searching Process Topic Two: Factors that affect the search process Topic Three: Search Strategies Topic Four: Techniques for AIR Topic Five: Search Engines Florence O. Entsua-Mensah (Mrs) 4

4 Recommended Reading Rowley, J. (2015). The Changing Nature of Information Behaviour. In Encyclopedia of Information Science and Technology (3rd ed.). IGI Global. Kuhlthau, C. C. (2008). Seeking Meaning: A Process Approach to Library and Information Services. Libraries Unlimited. Retrieved from Xie, I. (2009). Information Searching and Search Models. In Encyclopedia of Library and Information Sciences, Third Edition (pp ). Florence O. Entsua-mensah (Mrs), DIS/SCDE Slide 5

5 Topic One THE SEARCHING PROCESS Florence O. Entsua-mensah (Mrs), DIS/SCDE Slide 6

6 What is Information Search? Information Search is a process, which people undertake to locate or retrieve specific information to meet an information need, typically, but not always with the aid of a search engine or other information retrieval system (Rowley, 2015). Information searching can be defined as users purposive behaviours in finding relevant or useful information in their interactions with information retrieval (IR) systems (Xie, 2010). Florence O. Entsua-Mensah (Mrs) 7

7 Categories of Information Searching Information searching can be categorized into intermediary information searching and end-user information searching. In intermediary searching, information professionals serve as intermediaries between users and the IR system in the search process, whereas in end-user searching, users directly search for information themselves. (Xie, 2009) Florence O. Entsua-Mensah (Mrs) 8

8 The Generic Information Search Process Source: Florence O. Entsua-Mensah (Mrs) 9

9 Cleverdon s Searching Process A database may comprise controlled or uncontrolled vocabulary. Cleverdon mentions that a user searching a database that has controlled index languages must do the following: (Cleverdon, 1988) Florence O. Entsua-Mensah (Mrs) 10

10 Cleverdon s Searching Process Cont d (Cleverdon, 1988) Florence O. Entsua-Mensah (Mrs) 11

11 An Information Search Model Search models are illustrations of patterns of information searching and the search process. Some of the models also identify the factors that influence the search process. (Xie, 2009) Florence O. Entsua-Mensah (Mrs) 12

12 A MODEL OF THE INFORMATION SEARCH PROCESS (ISP) 1. Initiation, when a person first becomes aware of a lack of knowledge or understanding and feelings of uncertainty and apprehension are common. 2. Selection, when a general area, topic, or problem is identified and initial uncertainty often gives way to a brief sense of optimism and a readiness to begin the search. 3. Exploration, when inconsistent, incompatible information is encountered and uncertainty, confusion, and doubt frequently increase and people find themselves in the dip of confidence [self doubt creeps in]. 4. Formulation, when a focused perspective is formed and uncertainty diminishes as confidence begins to increase. 5. Collection, when information pertinent to the focused perspective is gathered and uncertainty subsides as interest and involvement deepens. 6. Presentation, when the search is completed with a new understanding enabling the person to explain his or her learning to others or in someway put the learning to use. (Kuhlthau, 2008) Florence O. Entsua-Mensah (Mrs) 13

13 Kuhlthau Model of the Search Process Florence O. Entsua-Mensah (Mrs) 14

14 Revised Kuhlthau Model of the Search Process Florence O. Entsua-Mensah (Mrs) 15 (Kuhlthau, 2004)

15 Topic Two FACTORS AFFECTING THE SEARCH PROCESS Florence O. Entsua-Mensah (Mrs) 16

16 Factors Affecting the Search Process Information searching is affected by different types of factors, in which four main types determine the selection and application of different search strategies: 1. User goal and task 2. User knowledge structure 3. Design of IR systems 4. The social and organizational context. (Xie, 2009) Florence O. Entsua-Mensah (Mrs) 17

17 Factors Affecting the Search Process Cont d 1. User goal and task complexity of task and stages of task play major roles in influencing search strategies. Task complexity has systematic relationships with the types of information, information channels and sources needed. As the level of task complexity increases, more information channels and resources are required (Byström, 2002). 2. User knowledge structure Three types of knowledge are required for effective information searching: (i) IR knowledge; (ii) domain knowledge; and (iii) system knowledge. Florence O. Entsua-Mensah (Mrs) 18

18 Factors Affecting the Search Process Cont d 3. Design of IR systems The design of IR systems no doubt affects users in their selections of search strategies. 4. The social and organizational context. The social-organizational context also defines the environment that user system interactions take place. Mainly, the work environment influences how users determine their search strategies in the search process. In addition, cultural dimensions shape how users interact with IR systems Florence O. Entsua-Mensah (Mrs) 19 (Xie, 2009)

19 Topic Three SEARCH STRATEGIES Florence O. Entsua-mensah (Mrs), DIS/SCDE Slide 20

20 Information Search Strategy Defined A search strategy is a plan for the whole search (Bates, 1979). A search strategy involves multiple dimensions, such as a tactic a move made to further a search, intentions, resources, methods, and so on (Xie, 2009). Florence O. Entsua-Mensah (Mrs) 21

21 Developing a search Strategy The following can serve as a guide in designing a search strategy: Identifying your information need Choosing search terms Searching with keywords Searching for exact phrases Using truncated and wildcard searches Searching with subject headings Using Boolean logic Citation searching Florence O. Entsua-Mensah (Mrs) 22

22 Search Strategies Search strategies map out a plan for the entire search process. Thus, what the searcher will do at each stage in the search process. To execute the items in your search strategies however, you may need certain techniques, generally referred to as search techniques/ techniques for searching. Florence O. Entsua-Mensah (Mrs) 23

23 TECHNIQUES FOR AIR Florence O. Entsua-Mensah (Mrs) 24

24 Techniques for searching (1) Keyword search Boolean search + Implied Boolean Natural language search Proximity operators Truncation/wildcards Subject headings controlled vocabulary Thesaurus or Index Lecturer: Florence O. Entsua-Mensah (Mrs) 25

25 Techniques for searching(2) Keyword search standard ways of retrieving information from any electronic database, i.e. online library catalog, periodical database or Internet database. Keywords describe topic of research Can be individual words or a phrase Choose significant words & come up with synonyms Key word search available in almost all databases Lecturer: Florence O. Entsua-Mensah (Mrs) 26

26 Techniques for searching(3) Keyword search Many databases require explicit description of relationship between keywords eg alternative fuels being used in automobiles Alternative fuels: electricity, ethanol, natural gas, hydrogen fuel cells Automobiles: cars, vehicles, transportation, motor vehicle Lecturer: Florence O. Entsua-Mensah (Mrs) 27

27 Techniques for searching(4) Boolean search Boolean uses three common words as logical operators; AND, OR and NOT allows one to combine words and phrases to either limit or expand the search OR - connector that allows either word to be present in each record in results. Use OR to expand your search. Search Term Hits Adolescents 15,900,000 hits Teenagers 34,600,000 hits Adolescents or teenagers 46,500,000 hits Either 'adolescents' or 'teenagers' (or both) will be present in each record. Lecturer: Florence O. Entsua-Mensah (Mrs) 28

28 Techniques for searching(5) Boolean.. AND - connector that requires both words to be present in each record in results. Use AND to narrow your search. Adolescents AND teenagers 7,390,000 hits NOT - connector that requires first word be present in each record in results, but only if record does not contain second word. Adolescents NOT teenagers 27,100,000 hits Lecturer: Florence O. Entsua-Mensah (Mrs) 29

29 Techniques for searching(6) OR - allows either word to be present in each record in results Use OR to expand your search. adolescents OR teenagers Adolescents Teenagers Lecturer: Florence O. Entsua-Mensah (Mrs) 30

30 Techniques for searching(7) AND - requires both words to be present in each record in results Use AND to narrow your search. Adolescents AND teenagers Adolescents AND teenagers Adolescents Teenagers Lecturer: Florence O. Entsua-Mensah (Mrs) 31

31 Techniques for searching(8) NOT - requires first word be present in each record in results, but only if record does not contain second word. operator NOT is also used to make a more restrictive set Adolescents NOT teenagers Adolescent s Teenagers Lecturer: Florence O. Entsua-Mensah (Mrs) 32

32 Techniques for searching(9) Implied Boolean refers to search in which symbols are used to represent Boolean logical operators (+) represents AND the minus sign (-) represents NOT no sign at all as an OR relation. Examples: +scientific_revolution +women_ in _Europe Lecturer: Florence O. Entsua-Mensah (Mrs) 33

33 Techniques for searching(10) Phrase search enclosing phrase in quotation marks help ensure that database searches for those words as a group. database then searches for those word together in specific order you provided. Phrases or combinations of words scientific revolution" OR scientific_revolution Predetermined language in a user fill-in template all of these words (=AND) any of these words (=OR) must not contain (=NOT) Lecturer: Florence O. Entsua-Mensah (Mrs) 34

34 Techniques for searching(11) Truncation shortening a word or eliminating some characters from a longer term to pick up variants a form of the Boolean operator OR. items that share a common sequence of characters, even if they do not share all the same characters are put into single set process called wildcard search or stemming Lecturer: Florence O. Entsua-Mensah (Mrs) 35

35 Techniques for searching(12) Some databases allow certain symbols to be used for searching different forms of a word (such as plurals) or different spellings Check help screens of particular database to determine appropriate symbols to use. Symbols used in truncation asterisk (*) question mark (?) colon (:) plus sign (+) Lecturer: Florence O. Entsua-Mensah (Mrs) 36

36 Techniques for searching(13) adolescen* retrieves adolescent, adolescents, or adolescence (right truncation) teen##### would retrieve teens and teenager and teenagers *ship retrieves relationship, librarianship, friendship (left truncation) wom#n retrieves woman or women (middle truncation) Lecturer: Florence O. Entsua-Mensah (Mrs) 37

37 Techniques for searching(14) Natural language search easiest to understand, but many databases don't offer it as a function. search using regular spoken language, such as English. Ask database question or type sentence that describes information you are looking for database then uses programmed logic to determine keywords in sentence by their position in sentence. The Internet search service Ask.com offers natural language searching. Ask.com Lecturer: Florence O. Entsua-Mensah (Mrs) 38

38 Techniques for searching(15) Proximity operators (closeness) Allow location of one word within certain distance of another. symbols generally used in this type of search are w and n. w represents word "with(in)" and n represents word "near." type of search not available in all databases. Near Operator (Nx) finds words within x number of words from each other, regardless of order in which they occur. Example: television n2 violence would find "television violence" or "violence on television," but not "television may be the culprit in recent high school violence." Lecturer: Florence O. Entsua-Mensah (Mrs) 39

39 Techniques for searching(16) Within Operator (Wx) finds words within x number of words from each other, in order they are entered in search. Example: Franklin w2 Roosevelt would find Franklin Roosevelt or Franklin Delano Roosevelt or Franklin D. Roosevelt, but would not find Roosevelt Franklin. Lecturer: Florence O. Entsua-Mensah (Mrs) 40

40 Techniques for searching(17) Subject headings controlled vocabulary match search subject or concept with term used by indexer Two basic lists of subject headings consulted by reference librarians Library of Congress Subject Headings- lists the standard LC subject heading in alphabetical order Sears List of Subject Headings rough equivalent of the LC subject headings for smaller libraries. Lecturer: Florence O. Entsua-Mensah (Mrs) 41

41 Techniques for searching(18) results of an initial search reveal that article citations have subject headings or descriptors. Articles that have similar content will have same subject headings even if authors of articles used different terms to describe topic. For example, one author may use phrase "capital punishment" and another "death penalty." subject heading on both records will be same. Sometimes subject headings are hyperlinked can link to other articles with similar content. Lecturer: Florence O. Entsua-Mensah (Mrs) 42

42 Techniques for searching(19) Thesaurus or Index A list of subject headings used in particular database is often referred to as a thesaurus. Some databases have sophisticated thesauri that provide cross-references. Eg "death penalty, thesaurus might ask you to use "capital punishment" instead Some thesauri also include description of term, and a list of broader, narrower, and related terms. Lecturer: Florence O. Entsua-Mensah (Mrs) 43

43 Topic Three SEARCH ENGINES Florence O. Entsua-Mensah (Mrs) 44

44 Introduction to Search Engines The hub of modern (computerised) information retrieval systems are search engines. Search engines connect a users search with relevant collection, in a very intuitive manner. (web) Search Engine is a computer program that searches for and identifies items in a database that correspond to keywords or characters specified by the user, used especially for finding particular sites on the World Wide Web (Vivekavardhan, 2018). Florence O. Entsua-Mensah (Mrs) 45

45 Importance of Search Engines With over 8 billion web pages available, it is impossible to search for the information that is specifically need through all these pages manually. Search engines filter the information that is on the internet and transform it into results that each individual can easily access and use in a matter of milliseconds. (Khurana, 2014) Florence O. Entsua-Mensah (Mrs) 46

46 How does a search Engine Work? The search engine visits (every) web page that it can find, it builds an index which is a list of tokens such as words that are associated with pages (images, audio, video, etc.). This feature of the search engine is the CRAWLER. Bear in mind that standard/conventional search engines do not access the DEEP WEB. Deep Web: The portion of the web composed of specialty database, such as those housed by the US government. It is also called the invincible web. The illegal content on deep web is called the Dark Web. Florence O. Entsua-Mensah (Mrs) 47

47 Examples of Search Engines Google Bing Yahoo Ask.com AOL.com Baidu DuckDuckGo Yandex Florence O. Entsua-Mensah (Mrs) 48

48 Summary In today s class, we have examined the search process from a typical users perspective paying close attention to Kuhlthau s Model of the Information Search Process. We also explored the various search techniques for an effective search process. As well as the role of search engines in modern information retrieval. Florence O. Entsua-Mensah (Mrs) 49

49 Activity 6.1 (Class Activity) TECHNIQUES FOR SEARCHING Define your information need or formulate your topic. For example: The involvement of women in the scientific revolution of the 16 th -18 th centuries in Europe Identify keywords/concepts in the topic articles and prepositions not keywords ;For example : women, science, Europe, 16 th century Florence O. Entsua-Mensah (Mrs) 50

50 Activity 6.1 (Class Activity) Techniques for searching (2) Find synonyms for keywords/concepts broader terms, narrower terms or related terms, spelling variants, abbreviations, alternative words Eg: Women: gender, female ;Science: zoology, biology, medicine, etc; Europe: England, Italy, Germany, France, etc; 15 th, 17 th, 18 th, Enlightenment age Words and synonyms become search terms Use search tools (search engines, etc) Combine search terms with Boolean operators Florence O. Entsua-Mensah (Mrs) 51

51 Activity 6.2 Individual Assignment Using the following search process advice a student on how to search for academic information: Step 1: Develop a Topic. Select Topic. Identify Keywords.... Step 2: Locate Information. Search Strategy. Books, Journals... Step 3: Evaluate Information. Evaluate Sources.... Step 4: Write. Organize / Take Notes.... Step 5: Cite Sources. Citation Styles.... Step 6: Legal / Ethical Use. Copyright. Florence O. Entsua-Mensah (Mrs) 52

52 Activity 6.3 Watch the video from this URL: Florence O. Entsua-Mensah (Mrs) 53

53 References Rowley, J. (2015). The Changing Nature of Information Behaviour. In Encyclopedia of Information Science and Technology (3rd ed.). IGI Global. Kuhlthau, C. C. (2008). Seeking Meaning: A Process Approach to Library and Information Services. Libraries Unlimited. Retrieved from Kuhlthau, C. C. (1988). Developing a model of the library search process: Investigation of cognitive and affective aspects. Reference Quarterly 28 (2), pp Kuhlthau, C. C. (1991) Inside the search process: Information seeking from the user s perspective. Journal of the American Society for Information Science, 42 (5), pp UTA Libraries (2018). Research Process. Available at: Xie, I. (2009). Information Searching and Search Models. In Encyclopedia of Library and Information Sciences, Third Edition (pp ). Florence O. Entsua-Mensah (Mrs) 54