1. 1 CS 430: Information Discovery Lecture 14 Usability I

2. 2 Course Administration Assignment 2, late submission. All assignments submitted by 2 p.m. today will be accepted. This is a special concession because of my email problems over the past week. Assignment 3. Due date is moved to Monday, November 5 at 5:00 p.m.

3. 3 Information Discovery Repository Index User

4. 4 The Human in the Loop Search index Return hits Browse repository Return objects

5. 5 Browsing in Information Space x x x xx x x x x x x x x x Starting point Effectiveness depends on (a) Starting point (b) Effective feedback (c) Convenience

6. 6 Convenience of Browsing Rapid access to materials Physical objects Library or large private collection Similar items stored close together (classification) Online information Rapid delivery to desktop good system performance no administrative delays (authentication)

7. 7 Hierarchical browsing Level 2 Level 1 Level 0

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11. 11 Searching Changing users, changing user interfaces FromTo Trained user or librarianUntrained user Controlled vocabularyNatural language Fielded searchingUnfielded text Manually created recordsFull text Boolean algorithmsRanking methods Stateful protocolsStateless protocols

12. 12 Interface design The interface design is the appearance on the screen and the actual manipulation by the user Fonts, colors, logos, key board controls, menus, buttons Mouse control or keyboard control? Conventions (e.g., "back", "help")

13. 13 Principles of interface design Interface design is partly an art; there are general principles: Consistency -- in appearance, controls, and function. Feedback -- what is the computer system is doing? why does the user see certain results? Users should be able to interrupt or reverse actions Error handling should be simple and easy to comprehend Skilled users offered shortcuts; beginners have simple, well-defined options The user should feel in control

14. 14 Varieties of user interfaces End user interface. Allows a library user to search, browse, or retrieve known items. Librarian and system administrator interface. Provides services for an authenticated user to view, add, delete, or edit index records. Batch interface. Provides a method to index large numbers of digital objects automatically.

15. 15 Question 4: User Interfaces (from Discussion Class 5) It is frequently recommended that there should be separate user interfaces for different categories of users. (a) What features might be included? (b) What are the practical issues in implementing such a choice?

16. 16 Question 7: Success or Failure? (from Discussion Class 5) "Zero-hit outcomes occur on 30% of searches at some services,..." (a) Why do you think that this happens? (b) Is it necessarily bad? (c) What can be done to reduce the bad aspects? "Every time I search, I get 10,000 hits..." (d) Why do you think that this happens? (e) Is it necessarily bad? (f) What can be done to reduce the bad aspects?

17. 17 Disabilities What if the user: is visually impaired or color blind? does not speak English? is a poor typist?

18. 18 Evaluation of Usability Observing users (user protocols) Focus groups Measurements effectiveness in carrying out tasks speed Expert review Competitive analysis

19. 19 Croft's Top Ten Criteria 1. Integrated Solutions "A text retrieval system is a tool that can be used to solve part of an organization's information management problems. It is not often, however, the complete solution. "Typically, a complete solution requires other text-based tools such as routing and extraction, tools for handling multimedia and scanned documents such as OCR, a database management system for structured data, and workflow or other groupware systems for managing documents and their use in the organization." Croft 1995

20. 20 Croft's Top Ten Criteria 2. Distributed Information Retrieval There is a huge "demand for text retrieval systems that can work in distributed, wide-area network environments." "The more general problems are locating the best databases to search in a distributed environment that may contain hundreds or even thousands of databases, and merging the results that come back from the distributed search."

21. 21 Croft's Top Ten Criteria 3. Efficient, Flexible Indexing and Retrieval "One of the most frequently mentioned, and most highly rated, issues is efficiency. Many different aspects of a system can have an impact on efficiency, and metrics such as query response time and indexing speed are major concerns of virtually every company involved with text-based systems." "The other aspect of indexing that is considered very important is the capability of handling a wide variety of document formats. This includes both standards such as SGML, HTML, Acrobat, and WordPerfect [and] the myriad formats used in text-based applications..."

22. 22 Croft's Top Ten Criteria 4. 'Magic' "One of the major causes of failures in IR systems is vocabulary mismatch. This means that the information need is often described using different words than are found in relevant documents. Techniques that address this problem by automatic expansion of the query are often regarded as a form of 'magic' by users and are viewed as highly desirable."

23. 23 Croft's Top Ten Criteria 5. Interfaces and Browsing "Effective interfaces for text-based information systems are a high priority for users of these systems. The interface is a major part of how a system is evaluated,... Interfaces must support a range of functions including query formulation, presentation of retrieved information, feedback, and browsing."

24. 24 Croft's Top Ten Criteria 6. Routing and Filtering "Information routing, filtering and clipping are all synonyms used to describe the process of identifying relevant documents in streams of information such as news feeds... large number of archived profiles are compared to individual documents. Documents that match are sent to the users associated with the profile."

25. 25 Croft's Top Ten Criteria 7. Effective Retrieval "Contrary to some researchers' opinions, companies that sell and use IR systems are interested in effectiveness. It is not, however, the primary focus of their concerns." "... companies are particularly interested in techniques that produce significant improvements (rather than a few percent average precision) and that avoid occasional major mistakes."

26. 26 Croft's Top Ten Criteria 8. Multimedia Retrieval "The perceived value of multimedia information systems is very high and, consequently, industry has a considerable interest in the development of these techniques."

27. 27 Croft's Top Ten Criteria 9. Information Extraction "Information extraction techniques are designed to identify database entities, attributes and relationships in full text." Also known as data mining.

28. 28 Croft's Top Ten Criteria 10. Relevance Feedback "Companies and government agencies that use IR systems also view relevance feedback as a desirable feature, but there are some practical difficulties that have delayed the general adoption of this technique."

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