Presentation on theme: "Digital Library User Interface and Usability"— Presentation transcript:
1 Digital Library User Interface and Usability Week 8
2 GoalsDiscover elements of good interface design for digital libraries of various sortsConsider examples from DL usability evaluation as sources of insight.Look at the distinct requirements of interfaces to libraries of video and audio files
3 Caveat Note -- We have a whole class in User System Interface Everything in that class is relevant to User Interfaces for Digital LibrariesOne evening will not replace that course, nor will it capture all of the relevant factors.
4 Note - to do laterAt 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.
5 The challengeA 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:
6 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
7 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
8 Methods of evaluation Surveys Target user groups Ethnographic studies Focus groups from the intended audiencesEthnographic studiesAudio/video taped sessions of usersAnalysis of feedback and commentsDemographic analysis of beta tester registration dataLog analysisWe will consider in more detail next week as we look at quality measuresHill 97
9 Usability inspection of Digital Libraries To produce a product with high usabilityClient and user interviewsTask analysisUser class definitionsUsage scenariosIterative usability designPrototypingDesign walk-throughsUsability evaluationUnfortunately, 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
10 Evaluation Evaulation for any purpose has two major components FormativeDuring development, spot check how things are progressingIdentify problems that may prevent goals from being achievedMake adjustments to avoid the problems and get the project back on trackSummativeAfter development, see how well it all came outLessons 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.
11 Usability evaluation Lab-based formative evaluation After deployment Real and representative usersBenchmark tasksQualitative and quantitative dataLeads to redesign where neededAfter deploymentReal users doing real tasks in daily workSummative with respect to the deployed systemUseful for later versions
12 Usability inspection Lower cost option than full lab-based testing Applies to early designs, well-developed designs, and deployed systemsDoes not employ real usersExpert basedUsability engineering practitionersMay be guided by typical user tasksSeeks to predict usability problems that users will encounter.Hartson 04
13 Inspection categories User classesKnow your userExample from the cited study:Scientific researchers in computer scienceAdministratorsDo not use the regular interface, so not evaluatedUser tasksSearch for technical reports on a set of criteriaBrowse the collectionRegisterSubmitHarvestHartson 04
14 Search expanded Search options Simple search Advanced search All bibliographic fieldsGroup results by archiveSortAdvanced searchFocus on specific fields with filter optionsHartson 04
15 Results - 1 Submit and Harvest tasks not evaluated Specialized domain requirementsNeed evaluation with real users to do meaningful testingReport on Problems FoundUsability problem typesWording, consistencyFunctionalitySearch and browse functionalityProblem = anything that impacts the user’s task performance or satisfaction.Hartson 04
16 Categories of Problems General to most applications, GUIsWordingConsistencyGraphic layout and organizationUser’s model of the systemDigital Library functionalityBrowsingFilteringSearchingDocument submission functionsHartson 04
17 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, correctButton and tab labelsMenu choicesWeb linksCrucial to help users learn and understand functionalityEasiest problems to fix if someone with right skills is on the team.Hartson 04
18 Search and Browse functionality Pretty basic to what a DL does!18% of the problems were in that area.Designers consider these separate functionsUsers see them as extremely closely relatedFind the desired resourceShould be designed togetherHartson 04
19 “Usual Suspects”Digital libraries prone to the same design faults as other interactive systemsConsistency“group” and “archive” used interchangeablyDifferent labels for the same concept used in different placesSimple search on tab, Search all bibliographic field at function locationMultiple terms referring to the same concept confuse users, slow learningStandardize terminology and check it carefullyHartson 04
20 Usual Suspects - 2 Problems with Feedback Clearly indicate where the user is in the overall systemClicking 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
21 Usual suspects - 3 Wording Use of jargon or slang, or unclear or missing labelsChallenge for usersExample in NCSTRLSeveral 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
22 Usual suspects - 4 Wording, continued Example: Submit to CoRR tabCould be “Submit Technical Report(s) to CoRRExample: Search all bibliographic fieldsCould be “Simple Search: Search all bibliograhic fields in selected archive (or for selected institution”Other examples of unclear labelsArchive’s Set - technical term from OAI-PMHDateStampDiscovery DateLabel for the user, not the developerHartson 04
23 Usual Suspects - 5 Incorrect or inappropriate wording “Search results” label for browsing resultshits (1-n) or total xxx hits displayedNot search results, just reports available for browsingApparent use of combined code for browse and search.Label results appropriately, even scrupulously, for their real meaning.Hartson 04
24 Usual suspects - 6 Appropriate terms Use of “hits” for individual search (or browse) resultsCommonly usedInappropriate slang, according to usability expertsConsidered unattractive, even slightly offensiveRecommended: something like “Matches with search term”Cosmetic consideration can have a positive affect on user’s impression of the site.Hartson 04
25 Layout and designThe 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 needsExample problems in the NCSTRL evaluationMenu choices - no logical orderReorganize by task or functionalityOrganize task interfaces by categories to present a structured system model and reduce cognitive workload.Hartson 04
26 Layout example Instead of randomly ordered tabs, group them by Information linksAbout NCSTRLAbout CoRROAIHelpUser tasksSimple searchAdvanced searchBrowseRegisterSubmit technical reports to CoRRHartson 04
27 Graphical designProximity of elements suggests associations and relatednessSearch button very close to OR radio boxApplies equally to all parts of the dialogConsider the implications of placement and association of graphical elements.Hartson 04
28 Start off rightAny 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.
29 DL specific problems Searching, filtering, browsing User view: all are aspects of finding a needed resourceDeveloper 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
30 Iterative search Search is often implemented as a one-shot function. Users want to iterate on their query string to improve resultsNCSTRL 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 resultsNot available in NCSTRLExamples where it is available?Hartson 04
31 Browsing NCSTRL allows browsing only by institutions (archive) Other possibilitiesDateAuthorSubjectAllow user activity that will serve user needs. Try to find out what users want before making decisions about services offered.
32 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 problemDoes the portal add service, or just provide a link to a collection of other sites?Hartson 04
33 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
34 Summary for NCSTRL case System exhibited many typical problems with user interfacesInvestigation illuminated some issues specific to digital libraries or other systems for retrieving information.
35 Another Case - CITIDEL CITIDEL I N T E R Dispatch routines Custom HTTP CITIDEL Databases-- Resource metadata-- Users and AccountsMySQLDatabasePerl Page Generation ModulesApache HTTP serverCustom HTTPHandlerDispatch routinesOpen Archives Initiative (OAI) InterfaceCITIDELXSL TemplatesHTML pagesEnd Users-- Educators-- Students-- Researchers-- ProfessionalsOther Digital Librariesand metadata indicesINTERCustom Search Engine (ESSEX)
36 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 CITIDELNo way to submit a resource (only accepts metadata for resources located elsewhere)Is that an issue? Why or why not?Design of the front pageCluttered, confusingWhat is really essential? What is useful? How should it be organized?
38 Video Digital Libraries Video digital libraries offer more challenges for interface designInformation attributes are more complexVisual, audio, other mediaIndicators and controlling widgetsStart, stop, reverse, jump to beginning/end, seek a particular frame or a frame with a specified characteristicSource: Lee 02
39 Video Interface Features Video browsingText descriptionTranscriptSingle keyframeStoryboardOption re granularity of keyframe setInteractive hierarchical keyframe browserKeyframe slide showVideo summary playingPlaybackTranscript + playback synchKeyframe + playback synchText search + playback and/or keyframe synchCatalogingSemi-automatic toolManual toolThreshold adjustable before automatic segmentationTextual QueryNatural language (or keyword)Category or keyword list browsingAudio information for indexing, browsingIntelligent frame selectionSource: Lee 02
40 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
41 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 programWatching (part of) a video programRe-querying the video digital library and/or within a video programSource: Lee 02
42 Summarizing stages of information seeking and the interface elements that support them as described in four researchers’ work.Source: Lee 02
43 Granularity in Video Browsing AbstractionReducing the information available to a manageable, usable subsetTraditional video & audio browsingOne point of accessSequentialFast forwardDifficult to see the contentNeed to return to the beginning to repeat searchSource: Lee 02
44 Video Abstraction Levels to present: (from Shneiderman 98) Overview firstZoom and FilterDetails on DemandExample levels (from Christel 97)Title: text format, very high level overviewPoster frame: single frame taken from the videoFilmstrip: a set of frames taken from the videoSkim: multiple significant bits of video sequencesTime referenceSignificant in videoOptions include simple timeline, text specification of time of the current frame, depth of browsing unitSource: Lee 02
45 Keyframe browsing Extract a set of frames from the video Display each as a still imageLink each to play the video from that pointSelection is not randomVideo analysis allows recognitionSudden change of camera shotScenes with motion or largely stationaryVideo indexing based on frame-by-frame image comparisonSimilar to thumbnail browsing of image collectionsSource: Lee 02
46 Keyframe extraction for display on browsing interface Source: Lee 02
47 Keyframe extraction Manual Automatic Owner or editor explicitly selects the frames to be used as index elementsAutomaticSubsampling - select from regular intervalsEasy, but may not be the best representationAutomatic segmentation - break the video into meaningful chunks and sample eachShot boundary detection - note switch from one camera to another, or distinct events from one cameraSource: Lee 02
48 Displaying the framesOnce the key frames are selected, display them for effective user interactionStoryboardMiniaturized keyframes in chronological orderAka keyframe list or filmstripSlide showKeyframes displayed one at a timeHierarchically arrangedGood when content is structured
49 More detailFor much more detail about Video browsing and presentation, see Lee 02.
50 SummaryMuch of digital library user interface design and usability analysis is the same as that of other web servicesKeep the user central in the design phaseBe careful about word useOrganize the graphics and layout carefullyThink about the user experienceSome special considerations about DL usability have to do with DL servicesSearch, filter, browseConnections with other collections to which this is a portal
51 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 21-29Hartson, H. R., Shivakmar, P, and Perez-Quiñones (2004) “Usability inspection of digital libraries: a case study” International Joural of Digital Libraries 4: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.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 2002Shneiderman 98: Shneiderman, B (1998) Designing the user interface: strategies for effective human-computer interaction, 3rd edition (Addison Wesley Longman)