user support Types of user support quick reference, task specific - PDF document

user support • Issues chapter 11 – different types of support at different tim es – im plem entation and presentation both im portant – all need careful design user support • Types of user support – quick reference, task specific help, full explanation, tutorial • Provided by help and documentation – help - problem -oriented and specific – docum entation - system -oriented and general – sam e design principles apply to both Requirements Approaches to user support • Availability • Com m and assistance – continuous access concurrent to main application – User requests help on particular com m and • Accuracy and completeness e.g., UNI X m an, DOS help – help matches and covers actual system behaviour – Good for quick reference • Consistency – Assum es user know what to look for – between different parts of the help system and paper documentation • Robustness • Command prompts – correct error handling and npredictable behaviour – Provide inform ation about correct usage when an • Flexibility error occurs – allows user to interact in a way appropriate to experience and task – Good for sim ple syntactic errors • Unobtrusiveness – Also assum es knowledge of the com m and – does not prevent the user continuing with work wizards and assistants Approaches to user support (ctd) • Context sensitive help • wizards – help request interpreted according to context in – task specific tool leads the user through task, step by step, which it occurs. e.g. t ooltips using user’s answers to specific questions • On-line tutorials – example: resumé – useful for safe completion of complex or infrequent tasks – user works through basics of application in a test environm ent. – constrained task execution so limited flexibility – can be useful but are often in flexible. – must allow user to go back • On-line docum entation – paper docum entation is m ade available on com puter. • assistants – continually available in com m on m edium – monitor user behaviour and offer contextual advice – can be difficult to browse – can be irritating e.g. MS paperclip – hypertext used to support browsing. – must be under user control e.g. XP smart tags 1

Knowledge representation Adaptive Help Systems User modeling • Use knowledge of the context, individual user, task, dom ain and instruction to provide help • All help systems have a model of the adapted to user's needs. user – single, generic user (non-intelligent) • Problem s – user-configured model (adaptable) – knowledge requirem ents considerable – system-configure model (adaptive) – who has control of the interaction? – what should be adapted? – what is the scope of the adaptation? Knowledge representation Approaches to user modelling Domain and task modelling • Quantification • Covers – user m oves between levels of expertise – com m on errors and tasks – based on quantitative m easure of what he knows. – current task • Stereotypes • Usually involves analysis of com m and – user is classified into a particular category. sequences. • Overlay • Problem s – idealized m odel of expert use is constructed – representing tasks – actual use com pared to ideal – interleaved tasks – m odel m ay contain the com m onality or difference – user intention Special case: user behaviour com pared to known error catalogue Techniques for knowledge Knowledge representation Advisory strategy representation • rule based (e.g. logic, production rules) – knowledge presented as rules and facts • involves choosing the correct style of advice – interpreted using inference mechanism for a given situation. – can be used in relatively large domains. e.g. rem inder, tutorial, etc. • fram e based (e.g. sem antic network) – knowledge stored in structures with slots to be filled – useful for a small domain. • few intelligent help system s m odel advisory • network based strategy, but choice of strategy is still – knowledge represented as relationships between facts im portant. – can be used to link frames. • exam ple based – knowledge represented implicitly within decision structure – trained to classify rather than programmed with rules – requires little knowledge acquisition 2

Problems with knowledge Issues in adaptive help representation and modelling • I nitiative – does the user retain control or can the system direct the • knowledge acquisition interaction? – can the system interrupt the user to offer help? • Effect • resources – what is going to be adapted and what information is needed to do this? – only model what is needed. • interpretation of user behaviour • Scope – is modelling at application or system level? – latter more complex e.g. expertise varies between applications. Designing user support Presentation issues • How is help requested? – com m and, button, function (on/ off), separate • User support is not an ` add on’ application – should be designed integrally with the • How is help displayed? – new window, whole screen, split screen, system . – pop-up boxes, hint icons • Effective presentation requires • Concentrate on content and context of – clear, fam iliar, consistent language help rather than technological issues. – instructional rather than descriptive language – avoidance of blocks of text – clear indication of sum m ary and exam ple inform ation Implementation issues I s help What resources are available? – operating system command – screen space – meta command – memory capacity – application – speed Structure of help data I ssues – single file – flexibility and extensibility – file hierarchy – hard copy – database – browsing 3