Why it matter.System users often judgea system by its interface rather thanitsfunctionalityApoorlydesignedinterface cancause a user tomake catastrophic errors.Poor user interface design is the reason why so many software systems arenever usedlicrosoft Iateraet ExplorerlieresoftInternetExplorerX你不想妞除文伴吗？你想册除文件吗？取定liereseftInternetExplorerXlierosoftInternet Explores你想册就别，但是不要后悔！你是否真的想删除件吗？取消确定取消确定
Why it matter • System users often judge a system by its interface rather than its functionality • A poorly designed interface can cause a user to make catastrophic errors • Poor user interface design is the reason why so many software systems are never used 6
UI design principles.Userfamiliarity:The interface should be based on user-oriented terms and concepts rather thancomputerconcepts.E.g., an office system should use concepts such as letters, documents, folders etc.ratherthandirectories,fileidentifiers,etc.OOOmEE
UI design principles • User familiarity The interface should be based on user-oriented terms and concepts rather than computer concepts E.g., an office system should use concepts such as letters, documents, folders etc. rather than directories, file identifiers, etc
UI design principles.Consistency:Thesystemshoulddisplayanappropriatelevelofconsistency:Commandsandmenusshouldhavethesameformat,commandpunctuationshouldbe similar, etc.Microsoft Visual BaticMicintaltVixuaflatHetcanceOCanceHenxMicrocoft Visual Basic+Microoft Visual BasicaCancelHirnDKCarealHtb
UI design principles • Consistency The system should display an appropriate level of consistency Commands and menus should have the same format, command punctuation should be similar, etc
UI design principles.Minimalsurprise:If a command operates ina known way,the user should be ableto predict theoperationofcomparablecommands×OpenwebsiteLook in:iarchitectUpdatemanes(snip)Flename.OpenFlesof type:WordforWindows6.0 (".doc)Cancel
UI design principles • Minimal surprise If a command operates in a known way, the user should be able to predict the operation of comparable commands
UI design principles.Recoverability:The system should provide some resilience to user errors and allow the user torecoverfromerrors.Thismight include an undo facility,confirmation of destructiveactions,'softdeletes,etc.日50L开始文性插入设计切换动画剪切版式蛋置复制新建粘贴U红式君书OTH
UI design principles • Recoverability The system should provide some resilience to user errors and allow the user to recover from errors This might include an undo facility, confirmation of destructive actions, 'soft' deletes, etc