Transcript Digital Library User Interface and Usability

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 welldeveloped 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
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Client and user interviews
Task analysis
User class definitions
Usage scenarios
Iterative usability design
Prototyping
Design walk-throughs
Usability evaluation
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.
Source: Hartson 04
Evaluation
• Evaluation 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
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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
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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
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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 bibliographic 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
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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
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About NCSTRL
About CoRR
OAI
Help
– User tasks
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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
into 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
End Users
-- Educators
-- Students
-- Researchers
-- Professionals
Other Digital Libraries
and metadata indices
I
N
T
E
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N
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Custom
HTTP
Handler
Apache
HTTP
server
Dispatch
routines
XSL Templates
Perl Page
Generation
Modules
HTML pages
Custom Search
Engine
(ESSEX)
Open
Archives
Initiative
(OAI)
Interface
MySQL
Database
CITIDEL Databases
-- Resource metadata
-- Users and Accounts
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?
www.citidel.org
CITIDEL continued
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
Source: Lee 02
• Video browsing
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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 synch
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)
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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
Keyframe
extraction for
display on
browsing
interface
Source: Lee 02
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
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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
References
Adam, N., Holowczak, R., Halem, M., Lal, N., and Yesha, Y. “Digital Lbrary
Technical Committee” cimic.rutgers.edu/ieee_dltf.html
Christel 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 Journal of Digital Libraries 4: 108123
Hill, L., Dolin, R., Frew, J., Kemp, R., Larsgaard, M., Montello, D., Rae, M., and
Simpson, J. “user Evaluation: Summary of the Methodologies 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)