SIMS 213: User Interface Design & Development

Marti HearstThurs, March 18, 2004

Outline

How do people search for images?Current approaches:– Spatial similarity– Keywords

Our approach:– Hierarchical Faceted Metadata– Very careful UI design and testing

Usability StudyConclusions

How do people want to search and browse images?

Ethnographic studies of people who use images intensely find:– Find specific objects is easy

• Find images of the Empire State Building– Browsing is hard, and people want to use rich

descriptors.

Ethnographic Studies

Garber & Grunes ’92– Art directors, art buyers, stock photo researchers– Search for appropriate images is iterative– After specifying and weighting criteria, searchers view

retrieved images, then• Add restrictions• Change criteria• Redefine Search

– Concept starts out loosely defined, then becomes more refined.

Ethnographic Studies

Markkula & Sormunen ’00– Journalists and newspaper editors– Choosing photos from a digital archive

• Stressed a need for browsing• Searching for specific objects is trivial• Photos need to deal with themes, places, types of objects, views

– Had access to a powerful interface, but it had 40 entry forms and was generally hard to use; no one used it.

Query Study

Armitage & Enser ’97– Analyzed 1,749 queries submitted to 7 image and

film archives– Classified queries into a 3x4 facet matrix

• Rio Carnivals: Geo Location x Kind of Event– Conclude that users want to search images

according to combinations of topical categories.

Ethnographic Study

Ame Elliot ’02– Participants: Architects

Common activities:– Use images for inspiration

• Browsing during early stages of design– Collage making, sketching, pinning up on walls

• This is different than illustrating powerpoint

Maintain sketchbooks & shoeboxes of images– Young professionals have ~500, older ~5k

No formal organization scheme– None of 10 architects interviewed about their image collections used

indexes

Do not like to use computers to find images

Current Approaches to Image Search

Using Visual “Content”– Extract color, texture, shape

• QBIC (Flickner et al. ‘95)• Blobworld (Carson et al. ‘99)• Body Plans (Forsyth & Fleck ‘00)• Piction: images + text (Srihari et al. ’91 ’99)

– Two uses:• Show a clustered similarity space • Show those images similar to a selected one

– Usability studies:• Rodden et al.: a series of studies• Clusters don’t work; showing textual labels is promising.

Rodden et al., CHI 2001

Rodden et al., CHI 2001

Rodden et al., CHI 2001

Current Approaches to Image Search

Keyword based– WebSeek (Smith and Jain ’97)– Commercial image vendors (Corbis, Getty)– Commercial web image search systems– Museum web sites

A Disconnect

Why are image search systems built so differently from what people want?

– An image is worth a thousand words.– But the converse has merit too!

Some Challenges

Users don’t like new search interfaces.How to show lots more information without overwhelming or confusing?

Our Approach

Integrate the search seamlessly into the information architecture.Use proper HCI methodologies. Use faceted metadata

Example of Faceted Metadata:Medical Subject Headings (MeSH)

Facets 1. Anatomy [A] 2. Organisms [B] 3. Diseases [C] 4. Chemicals and Drugs [D] 5. Analytical, Diagnostic and Therapeutic Techniques and Equipment [E] 6. Psychiatry and Psychology [F] 7. Biological Sciences [G] 8. Physical Sciences [H] 9. Anthropology, Education, Sociology and Social Phenomena [I] 10. Technology and Food and Beverages [J] 11. Humanities [K] 12. Information Science [L] 13. Persons [M] 14. Health Care [N] 15. Geographic Locations [Z]

Each Facet Has Hierarchy

1. Anatomy [A] Body Regions [A01] 2. [B] Musculoskeletal System [A02] 3. [C] Digestive System [A03] 4. [D] Respiratory System [A04] 5. [E] Urogenital System [A05] 6. [F] …… 7. [G] 8. Physical Sciences [H] 9. [I] 10. [J] 11. [K] 12. [L] 13. [M]

Descending the Hierarchy

1. Anatomy [A] Body Regions [A01] Abdomen [A01.047] 2. [B] Musculoskeletal System [A02] Back [A01.176] 3. [C] Digestive System [A03] Breast [A01.236] 4. [D] Respiratory System [A04] Extremities [A01.378] 5. [E] Urogenital System [A05] Head [A01.456] 6. [F] …… Neck [A01.598] 7. [G] …. 8. Physical Sciences [H] 9. [I] 10. [J] 11. [K] 12. [L] 13. [M]

Descending the Hierarchy

1. Anatomy [A] Body Regions [A01] Abdomen [A01.047] 2. [B] Musculoskeletal System [A02] Back [A01.176] 3. [C] Digestive System [A03] Breast [A01.236] 4. [D] Respiratory System [A04] Extremities [A01.378] 5. [E] Urogenital System [A05] Head [A01.456] 6. [F] …… Neck [A01.598] 7. [G] …. 8. Physical Sciences [H] Electronics 9. [I] Astronomy 10. [J] Nature 11. [K] Time 12. [L] Weights and Measures 13. [M] ….

Our Approach

Integrate the search seamlessly into the information architecture.Use proper HCI methodologies. Use faceted metadata:– Generate pages from a database– More flexible than canned hyperlinks– Less complex than full search– Help users see where to go next and return to what

happened previously

Questions we are trying to answerHow many facets are allowable?Should facets be mixed and matched?How much is too much?Should hierarchies be progressively revealed, tabbed, some combination?How should free-text search be integrated?

The Flamenco Interface

Hierarchical facetsChess metaphor– Opening– Middle game– End game

Tightly Integrated SearchExpand as well as RefineIntermediate pages for large categories

What is Tricky About This?

It is easy to do it poorly– Yahoo directory structure

It is hard to be not overwhelming– Most users prefer simplicity unless complexity really

makes a difference

It is hard to “make it flow”– Can it feel like “browsing the shelves”?

Using HCI MethodologyIdentify Target Population– Architects, city planners

Needs assessment. – Interviewed architects and conducted contextual inquiries.

Lo-fi prototyping. – Showed paper prototype to 3 professional architects.

Design / Study Round 1. – Simple interactive version. Users liked metadata idea.

Design / Study Round 2: – Developed 4 different detailed versions; evaluated with 11

architects; results somewhat positive but many problems identified. Matrix emerged as a good idea.

Metadata revision. – Compressed and simplified the metadata hierarchies

Our Project History

Design / Study Round 3. – New version based on results of Round 2– Highly positive user response

Identified new user population/collection– Students and scholars of art history– Fine arts images

Study Round 4– Compare the metadata system to a strong,

representative baseline

New Usability Study

Participants & Collection– 32 Art History Students– ~35,000 images from SF Fine Arts Museum

Study Design– Within-subjects

• Each participant sees both interfaces• Balanced in terms of order and tasks

– Participants assess each interface after use– Afterwards they compare them directly

• Data recorded in behavior logs, server logs, paper-surveys; one or two experienced testers at each trial.

• Used 9 point Likert scales.• Session took about 1.5 hours; pay was $15/hour

The Baseline System

FloogleTake the best of the existing keyword-based image search systems

Comparison of Common Image Search Systems

System Collection # Results /page

Categories?

# Familiar

Google Web 20 No 27

AltaVista Web 15 No 8

Corbis Photos 9-36 No 8

Getty Photos, Art 12-90 Yes 6

MS Office Photos, Clip art

6-100 Yes N/A

Thinker Fine arts images

10 Yes 4

BASELINE Fine arts images

40 Yes N/A

swordsword

Evaluation Quandary

How to assess the success of browsing?– Timing is usually not a good indicator– People often spend longer when browsing is going

well.• Not the case for directed search

– Can look for comprehensiveness and correctness (precision and recall) …

– … But subjective measures seem to be most important here.

Hypotheses

We attempted to design tasks to test the following hypotheses:– Participants will experience greater search satisfaction, feel

greater confidence in the results, produce higher recall, and encounter fewer dead ends using FC over Baseline

– FC will perceived to be more useful and flexible than Baseline– Participants will feel more familiar with the contents of the

collection after using FC– Participants will use FC to create multi-faceted queries

Four Types of Tasks

– Unstructured (3): Search for images of interest – Structured Task (11-14): Gather materials for an art history

essay on a given topic, e.g.• Find all woodcuts created in the US• Choose the decade with the most• Select one of the artists in this periods and show all of their woodcuts• Choose a subject depicted in these works and find another artist who

treated the same subject in a different way.

– Structured Task (10): compare related images• Find images by artists from 2 different countries that depict conflict

between groups.

– Unstructured (5): search for images of interest

Other Points

Participants were NOT walked through the interfaces.The wording of Task 2 reflected the metadata; not the case for Task 3Within tasks, queries were not different in difficulty (t’s<1.7, p >0.05 according to post-task questions)

Flamenco is and order of magnitude slower than Floogle on average.– In task 2 users were allowed 3 more minutes in FC than in

Baseline.– Time spent in tasks 2 and 3 were significantly longer in FC

(about 2 min more).

Results

Participants felt significantly more confident they had found all relevant images using FC (Task 2: t(62)=2.18, p<.05; Task 3: t(62)=2.03, p<.05)

Participants felt significantly more satisfied with the results (Task 2: t(62)=3.78, p<.001; Task 3: t(62)=2.03, p<.05)

Recall scores:– Task2a: In Baseline 57% of participants found all relevant

results, in FC 81% found all.– Task 2b: In Baseline 21% found all relevant, in FC 77% found

all.

Post-Interface Assessments

All significant at p<.05 except simple and overwhelming

Perceived Uses of Interfaces

What is interface useful for?

6.44

5.475.91

4.91

7.97 7.91

6.646.16

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1.00

2.00

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Useful for mycoursework

Useful forexploring anunfamiliarcollection

Useful for findinga particular image

Useful for seeingrelationships b/w

images

SHASTA

DENALI

Baseline

FC

Post-Test Comparison

15 16

2 30

1 29

   

4 28

8 23

6 24

28 3

1 31

2 29

FCBaseline

Overall Assessment

More useful for your tasksEasiest to useMost flexible

More likely to result in dead endsHelped you learn more

Overall preference

Find images of rosesFind all works from a given period

Find pictures by 2 artists in same media

Which Interface Preferable For:

Facet Usage

Facets driven largely by task content– Multiple facets 45% of time in structured tasks

For unstructured tasks, – Artists (17%)– Date (15%)– Location (15%)– Others ranged from 5-12%– Multiple facets 19% of time

From end game, expansion from– Artists (39%)– Media (29%)– Shapes (19%)

Qualitative ObservationsBaseline:– Simplicity, similarity to Google a plus– Also noted the usefulness of the category links

FC:– Starting page “well-organized”, gave “ideas for what to search for”– Query previews were commented on explicitly by 9 participants– Commented on matrix prompting where to go next

• 3 were confused about what the matrix shows– Generally liked the grouping and organizing– End game links seemed useful; 9 explicitly remarked positively on

the guidance provided there.– Often get requests to use the system in future

Study Results Summary

Overwhelmingly positive results for the faceted metadata interface.Somewhat heavy use of multiple facets.Strong preference over the current state of the art.This result not seen in similarity-based image search interfaces.Hypotheses are supported.

Summary

Usability studies done on 3 collections:– Recipes: 13,000 items– Architecture Images: 40,000 items– Fine Arts Images: 35,000 items

Conclusions:– Users like and are successful with the dynamic faceted

hierarchical metadata, especially for browsing tasks– Very positive results, in contrast with studies on earlier iterations– Note: it seems you have to care about the contents of the

collection to like the interface