aUniversity de Trás-os-Montes e Alto Douro and INESC TEC Portugsl
bUniversity de Trás-os-Montes e Alto Douro Portugsl
a r t i c le i n f o
Keywords:
User-centered design Image-type representation People with intellectual disabilities Digital content
a b s t r a ct
PreviousfindingshaveshownthatuserswithintellectualdisabilitiesnavigatetheWebmoreeasilyandwith greaterinterestwhenimagesareusedtorepresenthyperlinks(Rocha,2008;2014;Rochaetal.,2012).Although imagescanbebetterfornavigationpurposes,thereisaneedtounderstandhowtheseimagesshouldbedesigned toenhanceusers’ interactionwithdigitalcontentforthisparticulargroupofpeople.Thepurposeofthisstudyisto measuretheuser’spreferenceforimage-typerepresentation(Object,ActionandUniverse),withinfourdifferent categories(music,movies,sports,games).Thesampleconsistedof20individualswithintellectualdisabilities, theiragesrangingfrom22to49yearsold.Theresultsshowedthattheypreferredlesscompleximages,namely objectrepresentativeimages,andthatcategorieshadnoeffect.
© 2017ElsevierLtd.Allrightsreserved.
1. Introduction
Since2008,wehavecollaboratedwithaninstitutionthatdevelops activitieswiththemaingoalofenhancingeducationalandprofessional skillsofpeoplewithintellectualdisabilities.Thiscollaborationintended tostudythedevelopmentofassistivetechnologiesandaccessiblecon- tentsand,ultimately,toenhancedigitalskillsofagroupofpeoplewith intellectualdisabilities.Inthiscontext,wefindthatpeoplewithintellec- tualdisabilitieshavegreatmotivationandwilltoaccessdigitalcontent (Rocha,2008;Rochaetal.,2009;2012a).Moreover,wehaveobserved thatwhenuserswithintellectualdisabilitiesnavigatethroughWebcon- tent,theypaymoreattentiontoandshowmoreinterestinimagesand neglecttextualcontent(wehave observedthattheytendtoclickon severalimagehyperlinksbutscarcelyclickontexthyperlinks)(Rocha, 2008;Rochaetal.,2012b).
Subsequentstudiesshowed oneof themajorproblems:they can- notautonomouslyperformaWebsearchtasktofindpre-defineddigital contentthroughtheusualmetaphor,i.e.,byusingthesearchfieldofa Websearchengineandinsertingakeyword(Rochaetal.,2012b;Rocha, 2014;Rochaetal.,2015).Thus,theusualmetaphorforWebsearch(i.e., insertingkeywords)isnotaccessibletouserswithintellectualdisabil- itiesbecausetheyhavelowliteracyskillswithrespecttowritingand reading(andforthistask,theymustidentify/recognisekeywordchar- actersandrespondbyusingthekeyboard)(Harryssonetal.,2004;Roh, 2004;Smalletal.,2005;Careyetal.,2005;Bohman,2007;Rocha,2008;
2014).
∗Corresponding author.
E-mail address: [email protected] (T. Rocha).
Theseoutcomesmotivatedustostudytheuseofimagestorepresent hyperlinks ontheweb.Imagesshouldbeeasytoidentifyandunder- standtoultimatelyenhancetheuserinteractionwithWebcontent,by circumventingthereadingandwritingabilitiesneededforthisspecific taskforthisspecificgroupofusers.
Intheliterature,wefoundthattherecommendations formaking Webcontentmoreaccessible,theWebContentAccessibilityGuidelines, version2.0,providedbytheWorldWideWebConsortium(W3C-WAI 2.0),donotdefinespecificguidelinesfordesigningimagehyperlinks;
theyonlysuggestthatalternativetextmustbeprovidedforanynon- textcontent(WAI,2008).Also,wediscoveredthatseveralauthorshave examinedtheuseofimagestonavigateorsearchcontent(Udenand Dix,2000;Dixetal.,2004;Sevillaetal.,2007;FreidmanandBryen, 2007; Zarin,2009),andothersdescribedtheimagecategoriestested (Wiebeetal.,2016).However,theydidnotprovideanyexplanation regardingtheimagedesignprocess(Howshouldimagesberepresented?
Whichcompositiontheyshouldhave?).Thus,itisimportanttoaddress thedesignofimagestostudythebestwaytorepresenthyperlinks.
Aswefocusonaspecificgroupof users,peoplewithintellectual disabilities,weintendtobasethestudyonauser-centreddesignphi- losophy.User-centreddesign,alsoknownasUsabilityEngineering,is thephilosophyofachievingmoreusablesystems(reducingerrors,im- provingproductivity, useracceptance,andsatisfaction)thatinvolves designinginterfacestofitthecapabilitiesandneedsoftheusersasan alternativetothepreviousphilosophyoftechnology-centreddesignthat requiredadaptationbythehuman(user)(Endsley,2016).
https://doi.org/10.1016/j.ijhcs.2017.09.003
Received 9 January 2016; Received in revised form 31 August 2017; Accepted 7 September 2017 Available online 22 September 2017
1071-5819/© 2017 Elsevier Ltd. All rights reserved.
Insum,ourmainobjectiveistomeasuretheuser’spreferencefor image-typerepresentation(Object,Action,andUniverse),withinfour different categories (music,movies, sports, games)throughout their preferences,byinvestigatingwhicharetheirmentalmodels.
Users’ preferencesasincludedintheuserexperience(UX)philoso- phyfocusonhavingadeep understandingof users,whattheyneed, what theyvalue, theirabilities, andalso theirlimitations (usability.
gov).Moreover,asdescribedintheISO9241–210definition“userexpe- rienceincludesalltheuser’ emotions,beliefs,preferences,perceptions, physicalandpsychologicalresponsesbehavioursandaccomplishments thatoccurbefore,duringandafteruse” (ISO9241-201,2010).
Thispaperisstructuredasfollows: first,theimage-typerepresen- tationdesignisexplained,wherewedescribethemodelsfollowedin theicondesignprocess;then,themethodsectionprovidesdetailedin- formationregardingtheparticipants(sample),materialsandapparatus andtheprocedures;afterwards,theresultsarepresented;followedby theirdiscussion,whereweunderlinethestudylimitations;and,finally, wepresentourconclusionsandfuturework.
1.2. Image-Typerepresentationdesign
AsNadin(1988)affirms,“todesignmeanstostructuresystemsof signs insuch away astomake possible theachievementof human goals:communication(asaformofsocialinteraction),engineering(as aformofappliedtechnicalrationality),business(asaformofshared efficiency),architecture,art,education,andetcetera.” (Nadin,1988).
Thisstudydoesnothaveasitsmainfocusonsemiotics,rather,we intendtostudyusers’ preferenceforimage-typerepresentationwithin specificcategoriesforpeoplewithintellectualdisabilities.Itisnotin- tendedtodeterminewhichspecificsignisthebesttorepresentacate- gory,because,although“Designprinciplesaresemioticbynature”,we mustunderstandhowimagesaredecodedtopresentsolutionsforimage- typerepresentationdesign.Forthat,wepresentthedefinitionofsignby PeirceandSaussure.
CharlesPeirce (Americanphilosopher) advancedthedefinitionof signas“somethingthatstandstosomeoneforsomethinginsomere- spectorcapacity” anddefinesthesignasatriadicrelationbetweenthe signvehicle(thephysicalformofthesign),asignobject(theaspectof theworldthatthesigncarriesmeaningabout)andaninterpretant(the meaningofthesignasunderstoodbyaninterpreter).
However,FerdinandSaussure(Swissprofessoroflinguistics)haspro- posedadifferentdefinitionforwhatasignis:theunityandcombination ofasignifierandthesignified(Bouquet,2004;Saussure,1996).Saus- surehasadvancedthedefinitionof signsastheunitybetween asig- nifier(theactualsignembodiedinsomematerialform,suchaswords orshapes)andthesignified(whatthesignissupposedtomean),be- comingadyadicrelation.Saussuresawthisrelationasbeingessentially arbitrary,motivatedonlybysocialconvention.
Peirce’striadicmodelpresentedmayserveasanoperationalmodel todecodeasign.Asthisauthordeterminesonlytheunityamongthe threecomponents,Object,RepresentationandInterpretation,thatrep- resentsasign.Furthermore,accordingtothisauthor,asign hasalso threefunctions:Semioticsasscienceofrepresentation,scienceofexpres- sionandscienceofknowledge.Specifically,Semioticsasscienceofrep- resentationimpliestheRepresentationandObject,i.e.,representation basedonresemblance,likeness,indexically(representationcausallyin- fluencedbytheobject);scienceofexpressionimpliesarelationbetween RepresentationandInterpretation,i.e.,therelationbetweensignsand theuser,definingwhatsignsareusedfor;and,thescienceofknowledge impliesInterpretationandObject(basedonacknowledgingdiversity, conventions,meaning).
Thecomponentsandfunctionsofasign areevident inFig.1,by thearrows(O toR-semioticsasa scienceof representation;RtoI semioticsasascienceofexpression;andItoO,semioticsasascience ofknowledge)(Nadin,1988).
Fig. 1. Peirce’s operational model (three components of a sign: R – Representation = that which represents; O – Object = that which is represented; and I – Interpretation = the pro- cess of interpretation).
Furthermore,thetwomajortheories(Peirce’striadicandSaussure’s dyadicmodels)describethewaysignsgaintheabilitytotransmitinfor- mation.Boththeoriesperceivethatthedefiningpropertyofthesignsis arelationbetweenseveralelements.Accordingtoboththeories,“signi- fier” isarepresentationthatisclosertotherealorthefactual,whereas
“signified” isarepresentationthatisfartherfromthereal,closertothe associatedconcepts.Thus“signified” ishardertodecode.InFig.2,three differentexamplesofmusiciconrepresentationareshown.Iconrepre- sentation1,whichisclosertothe“signifier”,isamorereal,factual, objectiverepresentation,whichissimplertorecognise.Iconrepresen- tation 2combinesitsgraphical representationwithits interpretation (modeofuse,action).Iconrepresentation3,whichisclosertothe“sig- nified”,ismorecomplexinmeaning,moresymbolicandabstractsince itisnottangible. Themusicalnoteimageisamorecomplexwayto representmusicandthereforethereisahigherlevelofdecodification associatedwithit.
Specifically, inFig.3, wepresentthePeirce’s operationalmodel, relatingthecomponentsandfunctionsofthesign withamusic-type representationexample.Thisrelationledustoconsiderthree image- typerepresentationformats,whichare:Object,Action,andUniverse.
Tobetterunderstandtheseformats,wepresentthefollowingexample:
Musiciconrepresentation.Wecandirectlyassociateaheadphonessign withtwocomponentsofthesign,theobjectandrepresentation(O-R) (whichwecalledOBJECTbecauseofitscloseconnectiontotherepre- sentation).Additionally,weassociateapersonlisteningtomusicwith theheadphonessignwithtwosigncomponents,therepresentationand interpretation(R-I)thatimposeexpressionandmovement(whichwe calledACTION).Finally,weassociateamusicalnotesignwiththetwo remainingcomponents,objectandinterpretation(O-I),whichrequires knowledgefortheirdecoding(whichwecalledtheUNIVERSE).
Inshort,wesoughttoevaluatedifferenttypesof imagerepresen- tations(Object,ActionandUniverse)tounderstandwhetherthereisa typeofrepresentationthatispreferredbypeoplewithintellectualdis- abilities.
2. Methods
Thisisaquasi-experimental,case-controlstudywithaquantitative focus.Itspurposeistoinvestigatetheimpactofimage-typeandicon categoryontheuser’spreference.
Fig. 2. Type representation vs decoding. example with music icon representation.
Fig. 3. Operational model – music icon representation example.
2.1. Sample
Withintheintellectual disabilitiesitisvery difficulttoachieve a homogeneousgroupofparticipants(evenwiththesamepathology),as theymayhaveseveralpathologiesandlevelsofseverity.Therefore,we identifiedothercharacteristics,suchas:theirliteracylevelanddigital skills(specifically,theirlevelofcomputerandinternetinteraction),to selecttheparticipants,hopingthiswaywecouldgetamorecohesive group.Thus,participantswerenot chosenonly onthebasisof their typeorlevelofdisabilitiesbutwereselectedtoensurethesamelevelof literacyandtechno-abilitieswithinthegroup.
Specifically,twentyindividualswithintellectualdisabilitiespartook inthisstudy,withagesrangingfrom22to49yearsold(eightwomen andtwelvemen).Theparticipantswereselectedbyaspecialeducation
teacherandapsychologist,thatworkedwiththemonadailybasis.They dividedtheparticipantsaccordingtotheirleveloflearningthrougha diagnostictestandknowledgeoftheirreadingandwritingskills(devel- opedinschoolcontext).Theirliteracylevelvariedbetweenkindergarten andprimaryeducation;specifically,fifteenhadakindergarten-levelof literacy,andfivehadlevelsbetweenthefirstandsecondyearsofpri- maryschool,asisdefinedin thePortugueseeducationsystemthatis equivalenttotheelementary schoolinUSAandCanada.Within the group,sevenusershadwritingandreadingskillscorrespondenttothe firstandsecondyearlevelsandtheotherscouldonlyreadandwrite theirnamesandidentifyallgraphemes(characters)autonomously.Also, theywerechosenaccordingtothelevelofautonomyintheaccomplish- mentof personaldailytasks, suchas:hygiene,feed,andotherdaily personalroutines.
Regarding the intellectual disabilities, the psychologist provided global information regarding the participants’ pathologiesand their severity levels(accordingtoDSM-V2013).Specifically,eightpartici- pantshadfoetalalcoholsyndrome,fivewereidentifiedasbeinginmild andthreeatmoderateseveritylevels;elevenparticipantshadDownSyn- drome,onehadasevereandtenmildintellectualimpairment;onepar- ticipanthadmeningococcaldisease(knownasbacterialmeningitis)and developedamoderatecognitiveimpairment(problemswiththinking, learningandmakingdecisions).Additionally,withinthegroup, four- teenparticipantshadnormalvision,andsixhadcorrected-to-normal vision.
ConcerningthecomputerandInternetinteraction,allparticipants partookinadigitalintegrationprogramthathadstartedintheirschool in2008.Thisprogramallowedthemtotrainandacquiretechnological abilities,specifically,intheuseofbasicfeatureswiththecomputer(such as:switchonandoff,openthebrowser,maximiseawindow,openaspe- cificsoftware),trainingofWebselection,manipulationandnavigation tasks.Also,theyusedseveraleducationalandentertainmentplatforms.
Allthese activitiesgavethemabilitieswiththemouse andkeyboard handlingandaredetailedinRocha’sstudies(Rocha,2008;Rochaetal., 2009;Rocha,2014;Rochaetal.,2015).
Allparticipantswerevolunteersandhadpermission(intheformof awrittenconsent)fromtheirparentsortutorstoperformthetests.
2.2. Materialsandapparatus
Theiconsselectedforthiscasestudywerecreatedtakingintocon- siderationUdenandDix(2000)guidelines.Theseauthorsstatedtheim- portanceofcreatingiconicinterfacesystems,addressingtheusermental modelandthaticonsshouldbedesignedtolooklikefamiliarobjects, correspondingtotheusers’ mentalmodels(UdenandDix,2000).
Inaccordancewiththisstatement,weneededtounderstandwhich weretheusers’ mentalmodelsbeforewestartedcreationoftheicons.
Inthisregard,weconductedindividualinterviewswiththeparticipants andaspecialeducationteacher,inwhichweaskedparticipantstolist theirfavouriteactivities(e.g.,listeningtomusic,goingtotheswimming pool,drawingandpainting,playingfootball,sewing,watchingmovies, anddoinglaundryandkitchenactivities).
Afterwards,weinvitedparticipantswithintellectualdisabilitiesto performadrawingactivity,inwhichtheyhadtomakedrawingsac- cordingtofourestablishedcategories,music,games,sports,movies,as weintendedtounveilwhichkindofrepresentationtheyweremorefa- miliarisedwith,revealingdataregardingtheirmentalmodels.
Themajorresultsfoundofthisactivitywerethattheydrewimages accordingtothethreetypesofrepresentations:“Object”;“Action”;and
“Universe”.Specifically,inthefirstrepresentationtype,weincludedall theiconsthatrepresentobjects;thiscategoryrelatestothe“OtoR” side ofthetriangleinFig.3,becausetheparticipantsknewtheobjectand drewarepresentationofit.Thistypeofrepresentationalsocorresponds tothesimplerform,asshowninFig.2.The“Action” typeofrepresen- tationcomprisedallthedrawingsthatexpressedanyform ofaction.
Thisactionwasperceivedfromiconsinwhichsimpleobjectsweredec- oratedwithstrokesthatindicatedaparticipant’sownrepresentationof thefunctionalityofthatobject(forexample,theparticipantmightindi- catethattheobject“projector” hasbeendecoratedwithstrokesinfront ofittorepresentthelightcomingoutoftheprojector),orthecombina- tionofelementspromotingthesensationofaction.Thistypeofrepre- sentationrelatestothe“RtoI” sideofthetriangleinFig.3anddenotes amorecomplexformofrepresentation,asshowninFig.2.Finally,the
“Universe” typeofrepresentationwasdefinedtobetheumbrellaforthe drawingsthatimpliedknowledgeofthecontextofthecategory(some- timesalsoknownasthe“universe” ofthatcategory).Thiscategoryis muchmorecomplexandisthereforehardertodecode.Forexample,in themusiccategory,someextendedknowledgeisneededtorepresenta soundwithamusicalnote,asoundwaveorahistogram.Thisrelatesto the“ItoO” sideofthetriangleofFig.3andtothemostcomplexform ofrepresentationshowninFig.2.Thisinformationwasimportant,be- causeitallowedtominimisethenumberoficonsdesignedaccordingto thesuggestionsoftheirdrawings.
Moreover,astheparticipantswerefamiliarwithdifferenttypesof representationsthroughtheirdailyactivities(experienceinnon-digital, digitalandWebcontexts),weselectedimagesthatparticipantshadseen orinteractedwithdirectlyorinthecontextofadigitalornon-digital interface.
Consideringthecollectedinformation(interviews,drawingactivity, andPortuguesesocialandculturaldigitalcontext),wetailoredthede- signoftheiconstofitintooneoffourcategories:music,movies,sports, andgames.Fig.4.
Insum,weusedthedataprovidedfromthedrawingactivityand includedotherrelevanticonsfoundinaWebcontext.Forinstance,we foundseveraliconsfortheatreontheweblike“aneyeonascreen” or“peoplewatchingamovie” whensearchingfortheatreicons.These iconsaredesignedwiththecombinationofseveralelementspromoting theactortheactionyouwanttoconvey.
Allimageswereiconsinduotone(blackandwhite),becausewein- tendedtoassessonlyimagerepresentationandnoothercharacteristics, suchascolour,artwork,orrealismoftherepresentation(thesevariables willbeconsideredinfuturework).
Thefollowingmaterialresourceswereused:a17inchdisplaywith resolutionof1280×1024pixelsandaneyetrackingdevice.Eachsub-
Table 1
Chi-square test results (p value) .
𝜒2 df P Cramer’s V Music 12.4 2 0.002 0.557 Movies 9.7 2 0.008 0.492 Games 14.8 2 0.001 0.608 Sports 11.2 2 0.004 0.529
jectsatdownatadistancefromthecomputerscreenthatdidnotexceed onemeter.Theindividual’seyemovementswererecordedbyaTobii Eye-TrackerX50(TobiiTechnologyAB,Danderyd,Sweden),whichused aCCDcamerapositionedunderthecomputerscreen,andthesoftware ClearView2.5.1.
2.3. Procedure
The experimental setupwas conductedwith oneparticipant ata time.Beforestartingthetests,theeyetrackingdevicewascalibrated.If thecalibrationstepwassuccessful,allimages,foreachcategory,were displayedonthescreen,withoutscrolling,ashasbeensuggestedinother studies(Roh,2004;Freemanetal.,2005;Smalletal.,2005).Onlyim- ageswerepresentedonthescreen,therewerenolabelsregardingcat- egoryorimage-type.Theresearcherasked“whatimagedoyouprefer” foraparticularcategory.
Then,participantswereaskedtochoosetheimagethatbestrepre- sentedeachcategorybypointingtothescreen.Thisprocedurewasper- formedtosimplifytheprocessofchoosingandtoeliminatethemouse interactioncomplexity.
Allparticipantsperformedfourtasks,eachonerelatedtothefour categories(music,movies,games,andsports).Toensurerandomness, wechangedtheorderinwhichthecategorieswereshown.
3. Results
Fig. 5shows theoverallresults of the image-typerepresentation choices.TherewasastrongpreferenceforObjectimage-typerepresen- tation,followedbyActionimage-typerepresentation,ineachcategory.
Additionally,therewaslittleornopreferenceforimagesrepresenting theUniverseimage-typerepresentation,andintwocategoriesofgames andsports,there wasnot asingle choiceforsuchimages. Thevari- ables,iconcategoryandimage-typerepresentation,werebothcategor- ical,andsinceeachparticipantmadeachoicein eachiconcategory, theywereconsideredtobematchedgroups.Thus,arepeatedmeasures logisticregressiontestwasusedtoidentifywhethertheiconcategory hadaninfluenceontheselectedimage-typerepresentation.Theresults indicatedthattheiconcategorywasnotstatisticallysignificant(Wald Chi-Square=5.943,p=0.114)ininfluencingtheselected image-type representation,aspresentedinFig.5.
TheresultswereanalysedusingChi-squaregoodnessoffitteststode- terminewhethertheobserveddataresultedfromasimplerandomevent (meaningthatwecouldnotreachaconclusion).Thus,theobservedval- uesweretestedagainsttheexpectedvalues,inwhichalltypesofrep- resentationhadequalprobabilities.Table1presentstheChi-squaretest results.
For each icon category, the Chi-squaretest conditions weremet (Yatesetal., 1999).Inthis particularcase,allexpectedcounts were greater than 5. In all categories, the null hypothesis was rejected (p<0.05);hence,theobserveddatadidnotoriginatefromasimpleran- domevent.
In Fig. 6, we presentthe detailed results of the Music category choices.Thesubjectsselectedatotalofsevendifferentimages.Thetop threeimageswerepiano(object),whichwasselectedbyeightpeople;
drum(object),selectedbythreepeople;andthegraphicshowingaper- sonlisteningtomusic(action),alsoselectedbythreepeople.Globally,
Fig. 4. Images created for the different categories.
Fig. 5. Global results for choice of image representation.
theparticipantspreferred70%iconsrelatedtoobjects;20%action;and 10%universe.
Regardingthemoviescategory,theresultsaresummarizedinFig.7. Resultsshowedawiderrangeofchoices,i.e.,tenimagesoutofatotal oftwelveimages.Themostselectedimageswerethevideocamera(ob- ject),whichwaspreferredbyeightindividuals,followedbytheclapper- board(object),film(object),andcinema(action),withtwoselections each.Inthetopchoices,threereferredtotheobjects,andonereferredto theaction.Overall,participantspreferred65%iconsrelatedtoobjects;
10%action;and15%universe.
InFig.8,wepresentthedetailedresultsofthegamescategory.From fifteenicons,sevenimageswereselectedbytheparticipants:thetwo cardsicon(object)wasthemostselectedone(sevenchoices);twodices icon(object),racketandball(object),andplayingchess(action)allhad threeselectionseach.AsshownintheFig.8,globally,theparticipants preferred75%iconsrelatedtoobjects;and25%action.
Theresults forsportscategory arepresentedinFig.9.Fromato- taloffifteenicons,siximageswereselected.Participantsselectedthe soccerball(object),withsevenselections;thepersonplayingfootball image(action),withfiveselections;thetennisball(object),withthree selections.Amongthetopchoices,tworeferredtotheobjectsandone referredtotheaction.Overall,theparticipantshada50%preference regardingobject,and50%action.
Next,wepresenttheresultsfromtheeyetrackerdata.Asmentioned before,theeyetrackingdevicewasusedasavalidationtooltoensure thatparticipantsactuallychosetheimagethattheypaidattentionto.
Theresultsyieldedinsightsregardingthestrategiestheyusedtocom- pletethetask.Wefoundthatthesubjectsexploredmostoftheicons, includingtheuniversetypeofrepresentations.Theheatmaps(agglom- eratedanalysisofthevisualexplorationpatternsofagroupofusers)are shownbelow(Fig.10).
ForeachiconanAreaofInterest(AOI)wasdefined.Theicons/AOIs werelabelled(“A” to“L” -MusicandMoviescategories;“A” to“O” - GamesandSportscategories),columnbycolumn,fromtoptobottom andfromlefttoright.Basedontheeyetrackerdata(durationandpo- sitionofeachfixation)thenumberanddurationofthefixationsinside eachAOIwerequantified.
Fig.11showsthatinmostcategories,exceptforthe“Sports” cat- egory,theiconsbelongingtotheObjectimage-typerepresentationre- ceivedmorefixations.Inthe“Sports” categorythenumberoffixations forafewparticipantswereverylarge,whichbiasedthemeanfixation countresults.Butifwelookatthenumberoftimes(oneforeachpar- ticipant)thateachimage-typerepresentationobtainedthehighermean fixationcount,theObjectimage-typerepresentationgetsthebestscore (Fig.12).Themeanfixationdurationresults,presentedinFig.13,also corroboratethesefindings.Theseresultsindicatethattheiconsbelong-
Fig. 6. Number of images selected for the “Music ” category.
Fig. 7. Number of images selected for “Movies ” category.
Fig. 8. Number of images selected for the “Games ” category.
Fig. 9. Number of images selected in the “Sports ” category.
Fig. 10. Heat map results by category (music, movies, games, and sports).
Fig. 11. Mean fixation count for each category.
Fig. 12. Number of fixation count wins for each category.
Fig. 13. Mean fixation duration for each category.
ingtotheObjectimage-typerepresentationattractedmoreattention, whichsupportsourfindings.
Theiconschosen bytheparticipantscorrespondmostof thetime (morethan83%)totheiconswiththehighestorthesecondhighest numberoffixationcountsortoaneighbouricon,indicatingthatusually theparticipantschosetheimagethattheypaidattentionto.
4. Discussion
Globally,theresultsshowedthatthegrouppreferredobjectrepre- sentativeimages.Thechoicesoftheseparticipantsfrequentlyrelatedto knownobjectsthattheyuseandseedaily.Inotherwords,itappears thattheypreferredimagesthatweresimplertodecodeandcloserto the“signifier” – thatis,imagesthatweremoreconcreteintheirrep- resentationorrepresentspecificobjects(seeFig.2).Theseresultsmay suggestthatsomecustomisationoftheimagesmaybeneededtomake themcoincidewitheverydayobjectsfamiliartoaspecificgroup.These behaviourswerealsoobservedintheheatmaps(Fig.10)andintheeye trackerdataanalysis(Figs. 11–13),showing thattheparticipantsfo- cusedmostoftheirattentionontheObjectandActionimage-type,thus possiblyindicatingtheirpreferencefortheObjectorActionrepresenta- tiveimagesaswellasdistancefromtheUniverseimage-type.Regarding theprocessofchoosingthepreferredimages,itwasobservedthatsub- jectsusuallychosetheimagethattheypaidmoreattentionto.
Specifically,inthemusiccategory(Fig.6),theparticipantspreferred imagesthatrepresentobjectsthattheyuseonadailybasis.Universe representativeimageswerealmostneverselectedbytheparticipants, possiblybecauseofalackofinterestinthisimage-type(assuggested bytheindividualheatmaps)orbecausetheparticipantsdidnotrecog- nisetheimagerepresentation.Theonlytwoparticipantsthatchosethis typeofrepresentationdidso becausetheyhadparticipatedinmusic classesasanextraactivityoutsidetheschool,e.g.,theirlevelofmusic literacywashigherandthisprobablychangedtheirknowledge/context regardingthiscategory.Anotherimportantaspectisthatabstractim- agesarecommonlyusedtorepresentsomedetailsofourenvironment (Marganic, 2010), andalso thistypeof imagesareverylikely tobe found(asanimagehyperlink)inadigitalenvironment,suchasthetre- bleclefandthemusicnote.Moreover,differentprinciplescanbeused fordesigningicons.Thechoiceofsignificanceforsignscanbebasedon
criteriasuchas,forinstance,easyremembering,easyguessing,relation topopulationstereotypes.Giventhemanydegreesoffreedomunder- lyingthedesignoficonicsigns,ageneralprincipleshouldprobablybe adoptedasadesignaidinordertohaveanintuitivecontextforguiding users.However,weareincreasinglydistancingourselvesfromtheneed forparallelismwiththerealworldtounderstandthevirtualcontext.A buttondoesnotneedtographicallylooklikearealbuttonsowecan understandit.Wearemovingtowardssimplificationanddetachment from therealenvironment.Ahigher levelofdecoding isneededfor abstraction(universe-typerepresentation)contentratherthanthefig- urative(object-typerepresentation).However,thedesignershouldbe awarethatthecontentmustbeaccessibleandusableforall,regardless oftheirindividualcapabilitiesorcharacteristics.
Theobtainedresults mayindicate thattheseUniverseimage-type representationswerenotselectedforthemusiccategorybymorepar- ticipants,becausetheydidnotassociatethosetypesofrepresentations withthecategory.
Inthemoviescategory(Fig.7),thechoicesoftheparticipantsre- sembledobjectsthatthesubjectssaweitherontelevisionorduringtheir visitstothecinema.Whenweaskedthemabouttheirchoices,theyiden- tifiedthevideocameraimageasthemoviescategory.
Inthegamescategory,thechoicesoftheparticipantswereobjects thattheyrecognisedandusedintheirplayactivities,primarilyinschool (Fig.8).Giventhatplayingcardswastheparticipants’ mostfrequent game,ineitheradigitalorphysicalenvironment,itwasnotsurprising thatthecardsimagewastheonemostselectedforthiscategory.
Also,inthesportscategory,theparticipants’ choicescoincidedwith objectrepresentativeimages(Fig.9).Footballhasanimportantrolein Portuguesesportseducation,andwhenweaskedtheparticipantsabout theirchoices,theyhighlightedthisfact.
Furthermore,asmentioned,twoofthecategories,gamesandsport, hadthreemoreimages(foratotaloffifteen)thantheothertwocat- egories(musicandmovies,atotaloftwelveimages).Theparticipants chosesevenandtenimagesinthemusicandmoviescategories,respec- tively;inthegamesandsportscategories,theychosesevenandsixim- agesintotal.Onemightexpectthatbyhavingmoreoptionsthenumber ofdifferentchoicesmadebytheparticipantswouldincrease,butthis hasnotoccurred.Thismayindicatethatitisthecategorythataffects thedispersionofchoicesandnotthenumberoficons.Thisresultalso
indicatesthatprobablytherearecategorieswherethereismoreconcor- danceanditwillbeeasiertoselectanappropriateimage,andothers wherethenumberofoptionsthatneedstobeconsideredishigher.
Inshort,inthisstudy,weinvestigatedthepreferencesofpeoplewith intellectualdisabilities.Theresultssuggestthatforpeoplewithintellec- tualdisabilitiesthebestimage-typerepresentationisobjectrepresenta- tion.
Theuseoficonstorepresentcategories,andthusnavigatewithina webpage,isacommonpracticeontheWorldWideWeb.Earlystudies haveshownthatpeoplewithintellectualdisabilitiesperformbetterin navigatingwebsiteswhenimagesareusedashyperlinks.Theresults obtainedprovideabasisforhowweshoulddirectoureffortstogive peoplewithintellectualdisabilitiestheautonomytoperformsomebasic tasksontheinternet. So,ifthey preferredobject-typerepresentative imagestoagivencategory,willtheyhavemoreautonomyonawebsite thatusesthisimage-typeofrepresentationfornavigationpurposes?Can thisfactincreaseusabilityandaccessibilityofthewebsites?
Careshouldbetakenwithinternalconsistency,andthusitmustbe clearwhichiconsrepresentnavigationalcontentandwhichareused onlyforaesthetics.Morestudiesareneededtoaddresstheseissuesand toachievethefinalgoalofaccessibilityforpeoplewithintellectualdis- abilities.
4.1. Limitationsofthestudy
Inthispaper,weinvestigatedthepreferencesofpeoplewithintel- lectualdisabilitiesregardingdifferentimage-typerepresentation;wedid notassessinterpretability.Thus,moreresearchisneededtounderstand whetherthepreferencesofthesubjectsareaffectedbytheirabilitiesto decodetheiconsorbytheaestheticsoftheimages.
Anotherlimitationcomesfromthefactthatsomeparticipantswere involvedintheimagedesignprocess,asdescribedinthematerialssec- tion.Thus,participantscouldbebiasedtochoosetheirdrawingsasthat iswhattheyaremorefamiliarwith.
Also,wedidnotrandomisetheiconswithineachcategory.Thus,we cannotstatewithagreatdealofconfidencethatparticipants’ choices arebasedontheirpersonalpreferenceandnotbecauseoftheirnatural languagereadingdirection.Furthertestsshouldbemadetoclarifythis issue.
5. Conclusionsandfuturework
Themaingoalofthisstudywastomeasuretheuser’spreferencefor image-typerepresentation(Object,ActionandUniverse), withinfour differentcategories(music,movies,sports,games),whichcanbeused ashyperlinksinadigitalnavigationcontext.Image-typerepresentation wasdesignedaccordingtothreetypesofrepresentation:Object(simpler todecode),Action,andUniverse(morecomplextodecode).
Theresultsshowedthattheparticipantspreferredobject-typerepre- sentativeimagesforallthecategoriestested(music,movies,sportsand games).Theirchoicewasinfluencedbyactivitiesandtasksthatthepar- ticipantsperformedandrecognisedonadailybasisatschoolorhome, indigitalornon-digitalenvironments.Imagesthatwerenotfamiliarin theparticipants’ dailylife,imagesmorecomplextodecodeandthose withanabstracttypeofrepresentationweremostlynotselected.
Theseresultsindicatethatimagehyperlinksdesignedasobject-type representation,becauseofits closeconnectiontotherepresentation, aresimplertodecode(Fig.2),andconsequently couldfacilitateWeb navigationofpeoplewithintellectualdisabilities.Webelievethatifwe designsystemswithhyperlinksthatcouldberepresentedbyimagesthat areeasilydecodedbypeoplewithintellectualdisabilities,itcouldhelp othergroupsofpeoplethatseetheirinteractiondiminishing,enhancing accessibilityofthesystem.
Furthermore,semioticsandculturalissuesassociatedwithimage- typerepresentation(suchascolour,shape,andperspective)andsociety aspects(suchasgender,age,geographicallocation,andsocio-economic
context)forbetterinterpretabilitybypeoplewithintellectualdisabil- itiesisatopicthatrequiresmoreresearch.Inthispaper,wedidnot intendtodeterminethebesticonforeachcategory,butinsteadtomea- suretheuser’spreferenceforimage-typerepresentation(Object,Action, andUniverse),withinfourcategories.
In futurework, we willstudy usability,wherewe willassess ef- fectiveness andefficiencyofhyperlinksfornavigationusingdifferent image-typerepresentations. Furthertests willbe conductedinwhich theicons’ orderwill berandomizedwithin eachcategory tobesure thatthenaturallanguagereadingdirectiondoesnotinfluencethepar- ticipants’ choices.Futurestudieswillalsoconsiderwhetherpreference andperformancearecorrelated.Additionally,weintendtostudyprefer- encesregardingimagecomposition(photography,colouredcartoonish andblack/whitedrawings)andimagesize.
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