2002.11.25 - slide 1is 202 – fall 2003 lecture 22: interfaces for information retrieval i prof....

2002.11.25 - SLIDE 1IS 202 – FALL 2003

Lecture 22: Interfaces for Information Retrieval I

Prof. Ray Larson & Prof. Marc Davis

UC Berkeley SIMS

Tuesday and Thursday 10:30 am - 12:00 pm

Fall 2002http://www.sims.berkeley.edu/academics/courses/is202/f03/

SIMS 202:

Information Organization

and Retrieval

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Lecture Overview

• Review of Last Time– Web Search Engines and Algorithms

• Interfaces for Information Retrieval– Introduction to HCI– Why Interfaces Don’t Work– Early Visions: Memex

• Discussion Questions

• Action Items for Next Time

Credit for some of the slides in this lecture goes to Marti Hearst

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Lecture Overview






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Directories vs. Search Engines

• Directories– Hand-selected sites– Search over the

contents of the descriptions of the pages

– Organized in advance into categories

• Search Engines– All pages in all sites – Search over the

contents of the pages themselves

– Organized after the query by relevance rankings or other scores

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Challenges for Web Searching: Data

• Distributed data• Volatile data/“Freshness”: 40% of the web

changes every month• Exponential growth• Unstructured and redundant data: 30% of web

pages are near duplicates• Unedited data• Multiple formats• Commercial biases• Hidden data

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Challenges for Web Searching: Users

• Users unfamiliar with search engine interfaces (e.g., Does the query “apples oranges” mean the same thing on all of the search engines?)

• Users unfamiliar with the logical view of the data (e.g., Is a search for “Oranges” the same things as a search for “oranges”?)

• Many different kinds of users

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Web Search Queries

• Web search queries are SHORT– ~2.4 words on average (Aug 2000)– Has increased, was 1.7 (~1997)

• User expectations– Many say “the first item shown should be what

I want to see!”– This works if the user has the most

popular/common notion in mind

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Search Engines

• Crawling

• Indexing

• Querying

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Standard Web Search Engine Architecture

crawl theweb

create an inverted

index

Check for duplicates,store the

documents

Inverted index

Search engine servers

userquery

Show results To user

DocIds

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Google

• Google maintains (currently) the world’s largest Linux cluster (over 15,000 servers)

• These are partitioned between index servers and page servers– Index servers resolve the queries (massively

parallel processing)– Page servers deliver the results of the queries

• Over 3 Billion web pages are indexed and served by Google

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Starting Points: What is Really Being Used?

• Today’s search engines combine these methods in various ways– Integration of directories

• Today most web search engines integrate categories into the results listings

• Lycos, MSN, Google

– Link analysis• Google uses it; others are also using it• Words on the links seems to be especially useful

– Page popularity• Many use DirectHit’s popularity rankings

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Ranking: Link Analysis

• Assumptions:– If the pages pointing to this page are good,

then this is also a good page– The words on the links pointing to this page

are useful indicators of what this page is about

– References: Page et al. 98, Kleinberg 98

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Ranking: Link Analysis

• Why does this work?– The official Toyota site will be linked to by lots

of other official (or high-quality) sites– The best Toyota fan-club site probably also

has many links pointing to it– Less high-quality sites do not have as many

high-quality sites linking to them

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Lecture Overview






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“Drawing the Circles”

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Human-Computer Interaction (HCI)

• Human– The end-users of a program– The others in the organization– The designers of the program

• Computer– The machines the programs run on

• Interaction– The users tell the computers what they want– The computers communicate results– The computer may also tell users what the computer

wants them to do

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What is HCI?

HumansTechnology

Task

Design

Organizational & Social Issues

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Shneiderman on HCI

• Well-designed interactive computer systems– Promote

• Positive feelings of success• Competence• Mastery

– Allow users to concentrate on their work, exploration, or pleasure, rather than on the system or the interface

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Design Guidelines

• Set of design rules to follow

• Apply at multiple levels of design

• Are neither complete nor orthogonal

• Have psychological underpinnings (ideally)

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Shneiderman’s Design Principles

• Provide informative feedback

• Permit easy reversal of actions

• Support an internal locus of control

• Reduce working memory load

• Provide alternative interfaces for expert and novice users

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HCI for IR

• Information seeking is an imprecise process

• UI should aid users in understanding and expressing their information needs– Help formulate queries– Select among available information sources– Understand search results– Keep track of the progress of their search

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Provide Informative Feedback

• About:– The relationship between query specification

and documents retrieved– Relationships among retrieved documents– Relationships between retrieved documents

and metadata describing collections

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Reduce Working Memory Load

• Provide mechanisms for keeping track of choices made during the search process

• Allow users to:– Return to temporarily abandoned strategies– Jump from one strategy to the next– Retain information and context across search

sessions

• Provide browsable information that is relevant to the current stage of the search process– Related terms or metadata– Search starting points (e.g., lists of sources, topic

lists)

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Interfaces For Expert And Novice Users

• Simplicity vs. power tradeoffs

• “Scaffolded” user interface

• How much information to show the user?– Number and complexity of user operations– Variants of operations– Inner workings of system itself– System history

• Example:– Television remote control

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User Differences

• Abilities, preferences, predilections– Spatial ability– Memory– Reasoning abilities– Verbal aptitudes– Personality differences– Age, gender, ethnicity, class, sexuality,

culture, education– Modalilty preferences/restrictions

• Vision, audition, speech, gesture, haptics, locomotion

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Nielsen’s Usability Slogans

• Your best guess is not good enough

• The user is always right

• The user is not always right

• Users are not designers

• Designers are not users

• Less is more

• Details matter

(from Nielsen’s “Usability Engineering”)

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Who Builds UIs?

• A team of specialists (ideally)– Graphic designers– Interaction / interface designers– Technical writers– Marketers– Test engineers– Software engineers– Enthnographers– Cognitive psychologists

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How to Design and Build UIs

• Task analysis

• Rapid prototyping

• Evaluation

• Implementation

Design

Prototype

Evaluate

Iterate at every stage!

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Task Analysis

• Observe existing work practices

• Create examples and scenarios of actual use

• Try out new ideas before building software

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Rapid Prototyping

• Build a mock-up of design

• Low fidelity techniques– Paper sketches– Cut, copy, paste– Video segments

• Interactive prototyping tools– Visual Basic, HyperCard, Director, etc.

• UI builders– NeXT, etc.

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Evaluation Techniques

• Qualitative vs. quantitative methods• Qualitative (non-numeric, discursive,

ethnographic)– Focus groups– Interviews– Surveys– User observation– Participatory design sessions

• Quantitative (numeric, statistical, empirical)– User testing– System testing

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Qualitative Questions

• User experience

• User preferences

• User recommendations

• “Design dialogue”

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Quantitative Questions

• Precision

• Recall

• Time required to learn the system

• Time required to achieve goals on benchmark tasks

• Error rates

• Retention of the use of the interface over time

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Lecture Overview






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Why Interfaces Don’t Work

• Because…– We still think of using the interface– We still talk of designing the interface– We still talk of improving the interface

• “We need to aid the task, not the interface to the task.”

• “The computer of the future should be invisible.”

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Norman on Design Priorities

1. The user—what does the person really need to have accomplished?

2. The task—analyze the task. How best can the job be done?, taking into account the whole setting in which it is embedded, including the other tasks to be accomplished, the social setting, the people, and the organization.

3. As much as possible, make the task dominate; make the tools invisible.

4. Then, get the interaction right, making things the right things visible, exploiting affordances and constraints, providing the proper mental models, and so on—the rules of good design for the user, written about many, many times in many, many places.

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Lecture Overview






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“What Dr. Bush Foresees”

Cyclops CameraWorn on forehead, it would photograph anything you see and want to record. Film would be developed at once by dry photography.

MicrofilmIt could reduce Encyclopaedia Britannica to volume of a matchbox. Material cost: 5¢. Thus a whole library could be kept in a desk.

VocoderA machine which could type when talked to. But you might have to talk a special phonetic language to this mechanical supersecretary.

Thinking machineA development of the mathematical calculator. Give it premises and it would pass out conclusions, all in accordance with logic.

MemexAn aid to memory. Like the brain, Memex would file material by association. Press a key and it would run through a “trail” of facts.

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Memex

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Memex Detail

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Cyclops Camera

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Vocoder: “Supersecretary”

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Investigator at Work

• “One can now picture a future investigator in his laboratory. His hands are free, and he is not anchored. As he moves about and observes, he photographs and comments. Time is automatically recorded to tie the two records together. If he goes into the field, he may be connected by radio to his recorder. As he ponders over his notes in the evening, he again talks his comments into the record. His typed record, as well as his photographs, may be both in miniature, so that he projects them for examination.”

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Memex

• “A memex is a device in which an individual stores all his books, records, and communications, and which is mechanized so that it may be consulted with exceeding speed and flexibility. It is an enlarged intimate supplement to his memory.”

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Associative Indexing

• “[…] associative indexing, the basic idea of which is a provision whereby any item may be caused at will to select immediately and automatically another. This is the essential feature of memex. The process of tying two items together is the important thing.”

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The WWW circa 1945

• “It is exactly as though the physical items had been gathered together from widely separated sources and bound together to form a new book. But it is more than this; for any item can be joined into numerous trails, the trails can bifurcate, and they can give birth to side trails.”

• “Wholly new forms of encyclopaedias will appear, ready-made with a mesh of associative trails running them, ready to be dropped into the memex and there amplified.”

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Selection

• “The heart of the problem, and of the personal machine we have here considered, is the task of selection. And here, in spite of great progress, we are still lame.

• Selection, in the broad sense, is still a stone adze in the hands of a cabinetmaker.”

—“Memex Revisited” (Bush 1965)

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Interaction Paradigms for IR

• Direct manipulation– Query specification– Query refinement– Result selection

• Delegation– Agents– Recommender systems– Filtering

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The “Adaptive” Memex

• “In an adaptive Memex, the owner has delegated to the machine the ability to propose or effect changes in the stored information. By analogy to business practice, the Memex is said to be functioning as an agent (Kay, 1984). The machine is playing an autonomous role within a restricted charter: to attempt a more effective organization of the information based on observations of actual use and topical similarities.”

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Lecture Overview






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Discussion Questions

• Alison Billings on MIR 10.1 – 10.3– In section 10 of Modern Information Retrieval Marti A.

Hearst touches on the difficulty untrained users face in doing Boolean searches (i.e. the misinterpretation of OR and AND, nets being cast too wide or too narrow) so I thought it best to rely on both our experience and the reading to address the following questions: In doing the Boolean searches for assignment 8, did you use the KWIC search function to help you sort through the documents you retrieved? Did it help you find the information you needed? Did you have to reformat your Boolean queries several times in order for them to return the results you expected? Is it reasonable to expect users to continue use Boolean searches when there are more effective search methods available?

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• danah boyd on “Why Interfaces Don’t Work”– While Norman frames his argument through users, tasks,

invisible tools, and make the right things visible, his examples are quite flawed.

– He spent the majority of the paper talking about the problems with set-up. Yesterday, i purchased a brand new 12" Mac to replace my battered one. Turned it on; it worked and connected to my wireless. Put a cable between it and my old one and sucked off all of the data, including the programs. I installed 2 new programs. Inserted them into the CD drive and dragged them from the disk to my Applications folder. They worked. Brand new machine and it was immediately functional and identical to my old one in less than 2 hours (copy time). Even the proprietary stuff like my Audible.com files just asked me if i wanted to assign them to this new machine.

– I opened up a Sidekick yesterday. Turned it on. It connected to T-Mobile, told me what my email address was, told me to sign on to AIM and voila it worked.

– Is set-up really the problem?

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• danah boyd on “Why Interfaces Don’t Work”– Norman argues to put the user first. What

user? Can you really design a mass-produced item that takes into consideration all users who use it?

– Take the keyboard. What size is chosen? I have small fingers and yet it's hard to find small keyboards.

– What are the consequences of designing for an "average" user?

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• danah boyd on “Why Interfaces Don’t Work”– Norman argues for a comparison to RL tasks, making the task

the priority. – Users have vastly different sets of tasks that they want, but the

majority of computer consumers use their computer to 1) communicate (email, IM, chatrooms, voice over IP); 2) find information on the Web (surf).

– Neither of these tasks has a comparable off-line equivalent. How can you do a task-first analysis without an interface when you don't have an offline model to work with? What are the problems with modeling this behavior off of physical metaphors?

– For example, we've conceptualized email to be a metaphor to mail. This has created more problems than trying to design for an entirely new behavior.

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• Jeff Towle on “As We May Think”– Vannevar Bush throws out quite a few ideas in this

piece. A large portion of his piece is an analysis of instances where and idea was not feasible at the time, but was later built into something successful. Is this the case with Bush's ideas? They were clearly not feasible when he wrote this, but are they now?

– Many of Bush's proposals sound very familiar. His description of 'dry photography' seems to closely match digital photography technology. His description of information trails is quite similar to hypertext. But are we still missing some of Bush's great ideas?

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• Denise Green on Memex II– Vannevar Bush suggests that Memex

"...merely supplements a [human] memory, does so precisely and comprehensively, and aids the process of recollection." At the heart of Memex are information trails, which Bush believes are similar in nature to trails of association in our brains. How does this model compare with current ideas about how the brain works?

– How are Memex trails related to today's hypertext, as used commonly on the Internet? How are they dissimilar?

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• Ryan Shaw on Memex Revisited– Bush emphasizes compression and rapid access as

the two most important developments for data-handling technology. In retrospect, he seems to have given networking short shrift. Given Bush's uncanny vision, why did he overlook the importance of the network?

– While the Memex is a marvelous idea, Bush's article on the topic betray certain biases in his views on who uses information and why. How might these biases have affected his beliefs about 1) the feasibility of actually building a Memex-like system and 2) the effects of such a system, were it to be built?

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Lecture Overview






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Next Time: HCI For IR

• Browsing– Visualizing collections and documents– Navigating collections and documents

• Searching– Formulating queries– Visualizing results– Navigating results– Refining queries– Selecting results

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Next Time: HCI for IR

• Interfaces for Information Retrieval

• Readings– MIR 10.4 – 10.10

2002.11.25 - slide 1is 202 – fall 2003 lecture 22: interfaces for information retrieval i prof....

Documents

data slide

retrieval slide

google slide

scores slide

mind slide

time web search engines

user docids slide

search engine interfaces