Deliverable 4.4 - INSEAD CALT

AtGentive IST-4-027529-STP - Attentive Agents for Collaborative Learners8.1 Appendix 1 - Usability heuristics8.1.1 Established heuristics 17HeuristicsAesthetic andminimalist designConsistency andstandardsError preventionFlexibility andefficiency of useHelp anddocumentationHelp users recognise,diagnose, & recoverfrom errorsMatch between systemand the real worldRecognition ratherthan recallUser control andfreedomVisibility of systemstatusDescriptionDialogues should not contain information which is irrelevant or rarely needed. Everyextra unit of information in a dialogue competes with the relevant units of informationand diminishes their relative visibility.Users should not have to wonder whether different words, situations, or actions meanthe same thing. Follow platform conventions.Even better than good error messages is a careful design which prevents a problemfrom occurring in the first place. Either eliminate error-prone conditions or check forthem and present users with a confirmation option before they commit to the action.Accelerators -- unseen by the novice user -- may often speed up the interaction forthe expert user such that the system can cater to both inexperienced andexperienced users. Allow users to tailor frequent actions.Even though it is better if the system can be used without documentation, it may benecessary to provide help and documentation. Any such information should be easyto search, focused on the user's task, list concrete steps to be carried out, and not betoo large.Error messages should be expressed in plain language (no codes), precisely indicatethe problem, and constructively suggest a solution.The system should speak the users' language, with words, phrases and conceptsfamiliar to the user, rather than system-oriented terms. Follow real-world conventions,making information appear in a natural and logical order.Minimise the user's memory load by making objects, actions, and options visible. Theuser should not have to remember information from one part of the dialogue toanother. Instructions for use of the system should be visible or easily retrievablewhenever appropriate.Users often choose system functions by mistake and will need a clearly marked"emergency exit" to leave the unwanted state without having to go through anextended dialogue. Support undo and redo.The system should always keep users informed about what is going on, throughappropriate feedback within reasonable time.17 {Nielsen, 2006 #125}Del 4.4: AtGentive Final Evaluation Report page 2