Digital Library User Interface and Usability

Week 8

Goals

• Discover elements of good interface design for digital libraries of various sorts

• Consider examples from DL usability evaluation as sources of insight.

• Look at the distinct requirements of interfaces to libraries of video and audio files

Caveat

• Note --– We have a whole class in User System

Interface– Everything in that class is relevant to User

Interfaces for Digital Libraries– One evening will not replace that course,

nor will it capture all of the relevant factors.

Note - to do later

• At the end of the class, I will ask you to do a reflection on the points raised. You will be asked to summarize the most important characteristics of a well-developed DL interface.

• As you continue your DL projects, be sure to apply the relevant components of these elements.

The challenge

• A user interface for digital libraries must display large volumes of data effectively. – Typically the user is presented with one or more overlapping

windows that can be resized and rearranged. – In digital libraries, a large amount of data spread through a

number of resources necessitates intuitive interfaces for users to query and retrieve information.

– The ability to smoothly change the user's perspective from high-level summarization information down to a specific paragraph of a document or scene from a film remains a challenge to user interface researchers.

Source: http://cimic.rutgers.edu/ieee_dltf.html

Expectations of Digital Libraries

• Provide at least those services available in traditional libraries

• … and more.

• A system is successful “only to the degree to which the vast majority of its intended users are able to use its intended functionality”

Hill 97

User-centered design

• “User-centered design for a digital library must include not only systems evaluation but also an understanding of the process of information seeking and use.”

• Compared to a “self-evident door handle” -- once you see it, you know what it does and how to use it. No instruction is necessary.

Hill 97

Methods of evaluation

• Surveys• Target user groups

– Focus groups from the intended audiences

• Ethnographic studies– Audio/video taped sessions of users– Analysis of feedback and comments

• Demographic analysis of beta tester registration data

• Log analysis– We will consider in more detail next week as we look at

quality measures

Hill 97

Usability inspection of Digital Libraries

• To produce a product with high usability– Client and user interviews– Task analysis– User class definitions– Usage scenarios– Iterative usability design– Prototyping– Design walk-throughs– Usability evaluation

Source: Hartson 04

Unfortunately, most developers look at usability analysis as something to do at the end of the development process as a final test, rather than as a part of the design process.

Evaluation• Evaulation for any purpose has two major

components– Formative

• During development, spot check how things are progressing• Identify problems that may prevent goals from being achieved• Make adjustments to avoid the problems and get the project

back on track

– Summative• After development, see how well it all came out• Lessons learned may be applicable to future projects, but are

too late to affect the current one.• Needed for reporting back to project sponsors on success of

the work.

Usability evaluation

• Lab-based formative evaluation– Real and representative users– Benchmark tasks– Qualitative and quantitative data– Leads to redesign where needed

• After deployment– Real users doing real tasks in daily work– Summative with respect to the deployed system– Useful for later versions

Usability inspection

• Lower cost option than full lab-based testing• Applies to early designs, well-developed

designs, and deployed systems• Does not employ real users• Expert based

– Usability engineering practitioners

• May be guided by typical user tasks• Seeks to predict usability problems that users

will encounter.

Hartson 04

Inspection categories• User classes

– Know your user– Example from the cited study:

• Scientific researchers in computer science• Administrators

– Do not use the regular interface, so not evaluated

• User tasks– Search for technical reports on a set of criteria– Browse the collection– Register– Submit– Harvest

Hartson 04

Search expanded

• Search options– Simple search

• All bibliographic fields• Group results by archive• Sort

– Advanced search• Focus on specific fields with filter options

Hartson 04

Results - 1

• Submit and Harvest tasks not evaluated– Specialized domain requirements– Need evaluation with real users to do meaningful

testing

• Report on Problems Found– Usability problem types

• Wording, consistency

– Functionality• Search and browse functionality

• Problem = anything that impacts the user’s task performance or satisfaction.

Hartson 04

Categories of Problems

• General to most applications, GUIs– Wording– Consistency– Graphic layout and

organization– User’s model of the

system

• Digital Library functionality– Browsing– Filtering– Searching– Document

submission functions

Hartson 04

Wording

• About 36% of the problems in the case • “Precise use of words in user interfaces is one of the

most important design considerations for usability”• Clear, complete, correct

– Button and tab labels– Menu choices– Web links

• Crucial to help users learn and understand functionality

• Easiest problems to fix if someone with right skills is on the team.

Hartson 04

Search and Browse functionality

• Pretty basic to what a DL does!• 18% of the problems were in that area.• Designers consider these separate

functions• Users see them as extremely closely

related– Find the desired resource– Should be designed together

Hartson 04

“Usual Suspects”

• Digital libraries prone to the same design faults as other interactive systems– Consistency

• “group” and “archive” used interchangeably• Different labels for the same concept used in different

places– Simple search on tab, Search all bibliographic field at

function location

• Multiple terms referring to the same concept confuse users, slow learning

– Standardize terminology and check it carefully

Hartson 04

Usual Suspects - 2

• Problems with Feedback– Clearly indicate where the user is in the

overall system• Clicking a tab does not result in highlighting or

any kind of feedback about which tab is the currently active choice.

• Selected institution (archive) highlighted when chosen, but not maintained after some other actions.

Hartson 04

Usual suspects - 3

• Wording– Use of jargon or slang, or unclear or missing labels

• Challenge for users• Example in NCSTRL

– Several dates used. The labels for the dates do not clearly described what each represents.

– “discovery date” which is different from “accession date”» Discovery date -- probably a developers term, and not

likely to be of interest to the user.

– Use terms that are meaningful to users without explanation whenever possible. Resist presenting data that is not useful for user purposes.

Hartson 04

Usual suspects - 4

• Wording, continued– Example: Submit to CoRR tab

• Could be “Submit Technical Report(s) to CoRR

– Example: Search all bibliographic fields• Could be “Simple Search: Search all bibliograhic fields in

selected archive (or for selected institution”

– Other examples of unclear labels• Archive’s Set - technical term from OAI-PMH• DateStamp• Discovery Date

• Label for the user, not the developer

Hartson 04

Usual Suspects - 5

• Incorrect or inappropriate wording– “Search results” label for browsing results– hits (1-n) or total xxx hits displayed

• Not search results, just reports available for browsing

– Apparent use of combined code for browse and search.

• Label results appropriately, even scrupulously, for their real meaning.

Hartson 04

Usual suspects - 6

• Appropriate terms– Use of “hits” for individual search (or browse) results

• Commonly used• Inappropriate slang, according to usability experts• Considered unattractive, even slightly offensive• Recommended: something like “Matches with search term”

– Cosmetic consideration can have a positive affect on user’s impression of the site.

Hartson 04

Layout and design

• The whole point of a graphical user interface is to convey more information to the user in a short time.– The GUI must support the user needs

• Example problems in the NCSTRL evaluation– Menu choices - no logical order– Reorganize by task or functionality

• Organize task interfaces by categories to present a structured system model and reduce cognitive workload.

Hartson 04

Layout example

• Instead of randomly ordered tabs, group them by – Information links

• About NCSTRL• About CoRR• OAI• Help

– User tasks• Simple search• Advanced search• Browse• Register• Submit technical reports to CoRR

Hartson 04

Graphical design

• Proximity of elements suggests associations and relatedness– Search button very close to OR radio box– Applies equally to all parts of the dialog

• Consider the implications of placement and association of graphical elements.

Hartson 04

Start off right

• Any application should have a home page that explains what the site is about and gives the user a sense of the overall site capability and use.

• NCSTRL starts with the Simple Search page, with no introduction.

DL specific problems

• Searching, filtering, browsing– User view: all are aspects of finding a needed

resource– Developer view: differences based on what must

go in an index to support searching, how filtering is combined with searching to form a new query, etc.

• Usability suggestion: combine search, browse, filter into one selection and navigation facility.– Give users the power to combine these elements

to serve their needs.

Hartson 04

Iterative search

• Search is often implemented as a one-shot function. – Users want to iterate on their query string to

improve results• NCSTRL does not show the query that produced the

given results.

– Users want to prune the result set by applying a subsequent query to just those results

• Not available in NCSTRL• Examples where it is available?

Hartson 04

Browsing

• NCSTRL allows browsing only by institutions (archive)– Other possibilities

• Date• Author• Subject

• Allow user activity that will serve user needs. Try to find out what users want before making decisions about services offered.

Portal

• “A portal <is> a single point of access to distributed systems that provides services to support user needs to search, browse, and contribute content, often linking to shared existing functionality at other sites.”

• Portal pass through problem– Does the portal add service, or just provide

a link to a collection of other sites?

Hartson 04

Portal - submission

• NCSTRL - submission to CoRR• Link opens to another page, not directly

offering the opportunity to submit.• Disconnect for the user between the

original page and the action promised.• Link directly to the service offered

without any intermediate pages unless needed in support of the service.

Hartson 04

Summary for NCSTRL case

• System exhibited many typical problems with user interfaces

• Investigation illuminated some issues specific to digital libraries or other systems for retrieving information.

Another Case - CITIDEL

CITIDEL Databases -- Resource metadata -- Users and Accounts

MySQLDatabase

Perl Page Generation Modules

Apache HTTP server

Custom HTTPHandler

Dispatch routines

Open Archives Initiative (OAI) Interface

CITIDEL

XSL Templates

HTML pages

End Users -- Educators -- Students -- Researchers -- Professionals

Other Digital Librariesand metadata indices

INTERNET

Custom Search Engine (ESSEX)

CITIDEL• Practical issue

– What would be the results of applying a usability review to CITIDEL, similar to that applied to NCSTRL?

• A few extra notes that come up in examining CITIDEL– No way to submit a resource (only accepts metadata

for resources located elsewhere)• Is that an issue? Why or why not?

– Design of the front page• Cluttered, confusing• What is really essential? What is useful? How should it be

organized?

CITIDEL continued

www.citidel.org

Video Digital Libraries

• Video digital libraries offer more challenges for interface design– Information attributes are more complex

• Visual, audio, other media

– Indicators and controlling widgets• Start, stop, reverse, jump to beginning/end,

seek a particular frame or a frame with a specified characteristic

Source: Lee 02

Video Interface Features

• Cataloging– Semi-automatic tool– Manual tool– Threshold adjustable before

automatic segmentation

• Textual Query– Natural language (or

keyword)– Category or keyword list

browsing– Audio information for

indexing, browsing

• Intelligent frame selection

• Video browsing– Text description– Transcript– Single keyframe– Storyboard– Option re granularity of keyframe

set– Interactive hierarchical keyframe

browser– Keyframe slide show– Video summary playing– Playback– Transcript + playback synch– Keyframe + playback synch– Text search + playback and/or

keyframe synchSource: Lee 02

Common features for Video DLs

• Most systems use a textual querying interface and few systems provide any form of visual query interface, probably indicating the need for further development in this area;

• Most systems use keyframe(s) as their video browsing method;

• Playback is provided in all listed systems, indicating that playback is regarded as a most important interface feature;

• Whereas most systems provide more than one video browsing method (often transcript + playback and/or keyframe + playback), browsing aids such as synchronisation between different browsing methods are not often facilitated.

Source: Lee 02

Stages of Information seeking in Video Digital Libraries

• Browsing and then selecting video programs (as a collection)

• Querying within a video program (content querying)

• Browsing the content of a video program• Watching (part of) a video program• Re-querying the video digital library and/or

within a video program

Source: Lee 02

Summarizing stages of information seeking and the interface elements that support them as described in four researchers’ work.

Source: Lee 02

Granularity in Video Browsing

• Abstraction– Reducing the information available to a

manageable, usable subset

• Traditional video & audio browsing– One point of access– Sequential– Fast forward

• Difficult to see the content• Need to return to the beginning to repeat search

Source: Lee 02

Video Abstraction• Levels to present: (from Shneiderman 98)

– Overview first– Zoom and Filter– Details on Demand

• Example levels (from Christel 97)

– Title: text format, very high level overview– Poster frame: single frame taken from the video– Filmstrip: a set of frames taken from the video– Skim: multiple significant bits of video sequences

• Time reference– Significant in video– Options include simple timeline, text specification of time of the

current frame, depth of browsing unit

Source: Lee 02

Keyframe browsing

• Extract a set of frames from the video – Display each as a still image– Link each to play the video from that point

• Selection is not random– Video analysis allows recognition

• Sudden change of camera shot• Scenes with motion or largely stationary

– Video indexing based on frame-by-frame image comparison

• Similar to thumbnail browsing of image collections

Source: Lee 02

Source: Lee 02

Keyframe extraction for display on browsing interface

Keyframe extraction

• Manual– Owner or editor explicitly selects the frames to be

used as index elements

• Automatic– Subsampling - select from regular intervals

• Easy, but may not be the best representation

– Automatic segmentation - break the video into meaningful chunks and sample each

• Shot boundary detection - note switch from one camera to another, or distinct events from one camera

Source: Lee 02

Displaying the frames

• Once the key frames are selected, display them for effective user interaction– Storyboard

• Miniaturized keyframes in chronological order• Aka keyframe list or filmstrip

– Slide show• Keyframes displayed one at a time

– Hierarchically arranged• Good when content is structured

More detail

• For much more detail about Video browsing and presentation, see Lee 02.

Summary• Much of digital library user interface design and

usability analysis is the same as that of other web services– Keep the user central in the design phase– Be careful about word use– Organize the graphics and layout carefully– Think about the user experience

• Some special considerations about DL usability have to do with DL services– Search, filter, browse– Connections with other collections to which this is a portal

ReferencesAdam, N., Holowczak, R., Halem, M., Lal, N., and Yesha, Y. “Digital Lbrary

Technical Committee” cimic.rutgers.edu/ieee_dltf.htmlChristel 97: Christel, M., Winkler, D. and Taylor, C. (1997) “Multimedia abstractions

for a digital video library” Proceedings of the 2nd ACM International Conference on Digital Libraries (DL ‘97), Philadelphia, PA July, pp 21-29

Hartson, H. R., Shivakmar, P, and Perez-Quiñones (2004) “Usability inspection of digital libraries: a case study” International Joural of Digital Libraries 4: 108-123

Hill, L., Dolin, R., Frew, J., Kemp, R., Larsgaard, M., Montello, D., Rae, M., and Simpson, J. “user Evaluation: Summary of the Metholologies and Results for the Alexandria Digital Library, University of California at Santa Barbara. www.asis.org/annual-97/alexia.htm

Lee 02: Lee, H., and Smeaton, A. (2002) “Designing the User Interface for the Físchlár Digital Video Library” Journal of Digital Information, Volume 2, Issue 4 May 2002 http://jodi.tamu.edu/Articles/v02/i04/Lee/#2

Shneiderman 98: Shneiderman, B (1998) Designing the user interface: strategies for effective human-computer interaction, 3rd edition (Addison Wesley Longman)