On the design and development of UML-based visual

JournalofInformationTechnologyEducationVolume5,2006Editor:GlennLowryOntheDesignandDevelopmentofaUML-BasedVisualEnvironmentforNoviceProgrammersBrianD.MoorandFadiP.DeekCollegeofComputingSciences,NewJerseyInstituteofTechnology,Newark,NJ,[e-mail]@njit.eduExecutiveSummaryFewbeginnersfindlearningtoprogrameasy.Therearemanyfactorsatworkinthisphenomenonwithsomebeingsimplyinherentinthesubjectitself,whileothershavemoretodowithdeficien-ciesinlearningmethodsandresources.Asaresult,manyprogrammingenvironments,softwareapplications,andlearningtoolshavebeendevelopedtoaddressthedifficultiesfacedbynoviceprogrammers.Ofthesetools,visual-basedtoolsandtheuseofvisualizationhaveproventobeveryeffectiveinhelpingnovicesovercomeseveralofthesetraditionaldifficulties.Inthispaper,wefirstexaminethetraditionaldifficultiesthatnoviceprogrammersencounterwhentakeanin-troductory-levelprogrammingcourseareexamined.Itisimportanttogainanunderstandingofthescopeofthesedifficultiesfirst,astherestofthispaperconsidershowvisualtools,visualiza-tion,andUMLcanbeutilizedtoaidnovicedevelopersintheseareasofdifficulties.Next,weprovideananalysisofseveralmodernvisuallearningtools,includingEROSI,AnimPascal,BlueJ,FLINT,BOOST,andSOLVEIT.Inparticular,welookathowthesetoolsusevisualizationtohelpmitigatethedifficultiesnoviceprogrammersface.Eachtoolisalsoassessedbasedonitsoveralleffectivenessofusingvisualaidsandvisualizationtohelpthebeginningprogrammer.WethenturnourattentiontotheUnifiedModelingLanguage(UML)andhowitcanbeutilizedtohelpthenoviceprogrammerinsystemdesignandmodeling.TheUMLspecificationiscarefullydiscussed,andaspectsofthespecificationthatholdthemostpotentialforaidingnovicepro-grammersareidentified.Finally,wefocusonUMLmodelingandpresentthetheoreticalfounda-tionforanewvisuallearningtoolbasedontheUMLstandard.Thisproposedlearningenviron-mentattemptstocombinepromisingattributesofexistingtoolswepreviouslyexamined,alongwiththepotentialbenefitsofUML-basedmodeling.Theproposedtoolwouldprovideasuperiorlearningenvironmentforthenoviceprogrammerforseveralreasons.First,itisheavilybasedinthevisualdomain.Visualtoolshavecontinuallyproventobeextremelypowerfulinhelpingnov-icesinlearningabstractcomputerconcepts.Inaddition,visualizationhelpsnovicesconstructamentalmodelofconcepts,whichispivotaltofurthercomprehensionandunderstanding.Second,theproposedenvironmentwouldallowforaconstructivistlearningapproach,con-strainingtheUMLdomainfornovices,yeteasilyexpandedformorecomplexpro-jectsasthestudentprogresses.Finally,thistoolwouldnaturallyaidinsolutiondeliveryanddocumentationofthelearner’spathtosolution.Keywords:programming,novice,diffi-culties,UML,visualizationMaterialpublishedaspartofthisjournal,eitheron-lineorinprint,iscopyrightedbythepublisheroftheJournalofIn-formationTechnologyEducation.Permissiontomakedigi-talorpapercopyofpartoralloftheseworksforpersonalorclassroomuseisgrantedwithoutfeeprovidedthatthecop-iesarenotmadeordistributedforprofitorcommercialad-vantageANDthatcopies1)bearthisnoticeinfulland2)givethefullcitationonthefirstpage.Itispermissibletoabstracttheseworkssolongascreditisgiven.Tocopyinallothercasesortorepublishortopostonaserverortoredis-tribut[e-mail]-BasedVisualEnvironmentforNoviceProgrammers54BackgroundTraditionally,noviceprogrammershaveencountereddifficultiesinlearningtoprograminseveraldifferentareas,including:thecomprehensionoffundamentalcomputingconcepts,theappropriatedecompositionoftheproblemintoeasilymanagedsub-problems,designandimplementationofaworkingsolution,andthedebuggingoftheresultingprogram.Researchintheareaspsychologyofprogramming,human-computerinteraction,cognition,andpedagogyhaveidentifiedandclas-sifiedanumberoftheseproblemsthatnovicesfacewhenlearningtoprogram.BladekandDeek(2005)notethatnovicedifficultiescanbeadequatelyclassifiedintothefollowingcategories:pedagogicalroots,psychologicalroots,programminglanguageparadigms,programminglan-guageintricacies,debuggingskills,andexternalinfluences.Anineffectivepedagogyinlearningprogrammingisoneofthemostvitalfactorsthatwillinflu-encehowanoviceprogrammerwillperforminsubsequentexperiences.LiffickandAiken(1996)observethatbeginningprogrammersmaystumbleintheirunderstandingofanewconceptnotbecauseitisdifficult,butbecauseitisdependingonanearlierconcept.Anothercontributortoanineffectivepedagogycanbeattributedtothelackofadequateproblemsolvingskills.SuchanandSmith(1997)notethatasaresult,noviceprogrammersbegintowriteprogramsbutgeneratecodewithoutanyplanningororganizedthoughtprocess.Consequently,PaneandMyers(1996),aswellasOlson,Catrambone,andSoloway(1987)collectivelyobservethatgeneralproblemsolv-ingstrategiesshouldbeexplicitlyacquiredalongwithprogramdevelopmentskills.Agreatnumberofnovicedifficultieshavebeenclassifiedashavingpsychologicalroots.Withcomputers,themannerinwhichinformationisrepresentedandmanipulatedcausesachallengetoitsunderstanding.Asaresult,noviceslackanadequatementalmodelofthemachine’sinternals