CS 160 Lecture 22 Professor John Canny Spring 2003 01 14 19 1 Preamble Handout Reading for next time Note change to class schedule Quiz for last lecture 01 14 19 2 Help models What kind of help works best for you Do you ever read the manual Is help usually where you need it What are some differences between help you get from people and from systems 01 14 19 3 Types of Help Quick Reference Reminders of command names or options Task specific help User needs help on how to apply the command 01 14 19 4 Types of Help Full explanation User wants complete understanding e g for future use Tutorial The tutorial leads the user through a task scaffolding their actions 01 14 19 5 More advanced ideas Help is a kind of ongoing learning environment Minimalist instruction Carroll 92 is a learning approach It shows users what to do then gives them realistic tasks to solve It eliminates conventional exercises tedium and repetition and encourages users to explore It also has extensive coverage of error recovery users feel confident exploring 01 14 19 6 More advanced ideas Help could be enjoyable at least it s a special case of computer supported learning Training wheels Carroll Advanced commands are removed until user gains some experience with the system Also some dangerous commands Users explore freely in this sandbox Users gained better understanding IBM trial 01 14 19 7 More advanced ideas The scenario machine uses this idea and adds more help Explanations of why certain commands are missing Alternative command sequences for missing commands 01 14 19 8 Desiderata for help Availability Should be accessible anywhere always include a help key on each major window Accuracy and Completeness hard Make sure it matches program version and that it covers all the commands As well as commands common tasks should be described 01 14 19 9 Desiderata for help Consistency Content terminology style These days online and printed manuals are often the same Robustness Help shouldn t crash if the program does Program exceptions can bring up the help system 01 14 19 10 Desiderata for help Flexibility Includes adaption to context or user skill Multi level help is a good idea Unobtrustiveness Shouldn t disrupt users work like the annoying help characters in MS Office A separate help screen is often good supports rapid switching 01 14 19 11 Help in the days of yore Text command languages Unix DOS had explicit help commands man help Many design problems Shell kernel commands in one 90 page file Multiple OS and shell versions didn t match help Some commands self document with command Command help command h unfortunately this doesn t always happen No state to see the options again start over Emacs info was a better system early hypertext 01 14 19 12 Context sensitive help Help depends on where it is used Tool tips or the windows symbol Save the user the burden of synchronizing program state with help system state Almost always a good idea to do this Just make sure the user can easily find the main help contents and index 01 14 19 13 Online tutorials Can be useful BUT Users are not the same some need minimal help Forcing the user to execute a particular command is boring and annoying and doesn t help learning So Make sure users can skip steps Show users multiple ways of doing things Give partial information on what to do with more information available if the user requests it 01 14 19 14 On line docs Online docs differ from paper manuals in the same way web sites differ from books Information organization is the key Some pages contain content others are primarily for navigation Use best practices for web site design Intuitive names careful clustering of information intuitive link names consistency Need a good search feature and an index 01 14 19 15 Adaptive Help Systems Adaption is a good idea because It avoids information that is too detailed or not detailed enough for a particular user It avoids repetition of info the user has already seen Can make suggestions of new ways to do tasks that the user may not know Weaknesses Information can disappear bad if the user forgot it too System needs to know user identity and user must use the system for some time 01 14 19 16 User Models Beware Linear scales Novice competent expert people don t advance on the same path Stereotypes same as above plus users may have different kinds of problems in using the system 01 14 19 17 User Models Problematic Overlay model ideal behavior that the user should follow e g in tutorials But doesn t allow the user to do things their own way or explore Task modeling automatic task modeling is hard and doesn t model bottom up user behavior or distributed cognition e g desk as a blackboard 01 14 19 18 Knowledge representation Rule based techniques Limited success in AI but scales well Frame based techniques better organized version of RBT Semantic nets Decision trees Other AI stuff 01 14 19 19 Knowledge representation Generally the most successful KR techniques today use probabilistic models Particularly in HCI the system can t observe the user s expertise and can only guess what it is 01 14 19 20 Knowledge representation Probabilistic models provide a way to Allow several alternative interpretations at once Incorporate new evidence Model and explain the system s certainty in its own decisions Used in MS help system 01 14 19 21 Knowledge representation The trick is to figure out the appropriate traits of the user i e clusters of knowledge that users typically have You can mine help logs from user studies to identify these clusters or do it by inspection 01 14 19 22 Initiative A Help system works with the user and ideally should allow a spectrum of control Help me tell me what to do show me what to do OK I ll take over now This is called mixed initiative 01 14 19 23 Initiative A good mixed initiative help system requires links between all parts of the system including a tutorial User should be able to take over at any time then give back control 01 14 19 24 Effect Don t overdo user modeling The idea is to figure out just enough to adapt the help system Figure out the effects you need novice expert pages or specific task support and then the user data need to do adaption 01 14 19 25 Scope How much should help cover Common questions Functional model description Structural model info 01 14 19 26 Design issues Help system design is like other parts of the interface Start with task analysis Do paper prototypes Do user tests at informal and formal stages look
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