2nd part of Unit 1.ppt
- 1. • Designed to be different for UK and US customers • What are the differences and which is which? • What should Anna’s appearance be like for other countries, like India, South Africa, or China? Anna, IKEA online sales agent
- 2. Usability goals • Effective to use • Efficient to use • Safe to use • Have good utility • Easy to learn • Easy to remember how to use
- 3. Activity on usability • How long should it take and how long does it actually take to: – Using a DVD to play a movie? – Use a DVD to pre-record two programs? – Using a web browser tool to create a website? QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture.
- 4. User experience goals • satisfying • aesthetically pleasing • enjoyable • supportive of creativity • engaging • supportive of creativity • pleasurable • rewarding • exciting • fun • entertaining • provocative • helpful • surprising • motivating • enhancing sociability • emotionally fulfilling • challenging • boring • annoying • frustrating • cutsey
- 5. Usability and user experience goals • Selecting terms to convey a person’s feelings, emotions, etc., can help designers understand the multifaceted nature of the user experience • How do usability goals differ from user experience goals? • Are there trade-offs between the two kinds of goals? – e.g. can a product be both fun and safe? • How easy is it to measure usability versus user experience goals?
- 6. Design principles • Generalizable abstractions for thinking about different aspects of design • The do’s and don’ts of interaction design • What to provide and what not to provide at the interface • Derived from a mix of theory-based knowledge, experience and common-sense
- 7. Visibility • This is a control panel for an elevator • How does it work? • Push a button for the floor you want? • Nothing happens. Push any other button? Still nothing. What do you need to do? It is not visible as to what to do! From: www.baddesigns.com
- 8. Visibility …you need to insert your room card in the slot by the buttons to get the elevator to work! How would you make this action more visible? • make the card reader more obvious • provide an auditory message, that says what to do (which language?) • provide a big label next to the card reader that flashes when someone enters • make relevant parts visible • make what has to be done obvious
- 9. What do I do if I am wearing black? • Invisible automatic controls can make it more difficult to use
- 10. Feedback • Sending information back to the user about what has been done • Includes sound, highlighting, animation and combinations of these – e.g. when screen button clicked on provides sound or red highlight feedback: “ccclichhk”
- 11. Constraints • Restricting the possible actions that can be performed • Helps prevent user from selecting incorrect options • Physical objects can be designed to constrain things – e.g. only one way you can insert a key into a lock
- 12. Logical or ambiguous design? • Where do you plug the mouse? • Where do you plug the keyboard? • top or bottom connector? • Do the color coded icons help? From: www.baddesigns.com
- 13. How to design them more logically (i) A provides direct adjacent mapping between icon and connector (ii) B provides color coding to associate the connectors with the labels From: www.baddesigns.com
- 14. Consistency • Design interfaces to have similar operations and use similar elements for similar tasks • For example: – always use ctrl key plus first initial of the command for an operation – ctrl+C, ctrl+S, ctrl+O • Main benefit is consistent interfaces are easier to learn and use
- 15. When consistency breaks down • What happens if there is more than one command starting with the same letter? – e.g. save, spelling, select, style • Have to find other initials or combinations of keys, thereby breaking the consistency rule – e.g. ctrl+S, ctrl+Sp, ctrl+shift+L • Increases learning burden on user, making them more prone to errors
- 16. Internal and external consistency • Internal consistency refers to designing operations to behave the same within an application – Difficult to achieve with complex interfaces • External consistency refers to designing operations, interfaces, etc., to be the same across applications and devices – Very rarely the case, based on different designer’s preference
- 17. Keypad numbers layout • A case of external inconsistency 1 2 3 4 5 6 7 8 9 7 8 9 1 2 3 4 5 6 0 0 (a) phones, remote controls (b) calculators, computer keypads
- 18. Affordances: to give a clue • Refers to an attribute of an object that allows people to know how to use it – e.g. a mouse button invites pushing, a door handle affords pulling • Norman (1988) used the term to discuss the design of everyday objects • Since has been much popularised in interaction design to discuss how to design interface objects – e.g. scrollbars to afford moving up and down, icons to afford clicking on
- 19. What does ‘affordance’ have to offer interaction design? • Interfaces are virtual and do not have affordances like physical objects • Norman argues it does not make sense to talk about interfaces in terms of ‘real’ affordances • Instead interfaces are better conceptualized as ‘perceived’ affordances – Learned conventions of arbitrary mappings between action and effect at the interface – Some mappings are better than others
- 20. Activity – Physical affordances: How do the following physical objects afford? Are they obvious?
- 21. Activity – Virtual affordances How do the following screen objects afford? What if you were a novice user? Would you know what to do with them?
- 22. Usability principles • Similar to design principles, except more prescriptive • Used mainly as the basis for evaluating systems • Provide a framework for heuristic evaluation
- 23. Usability principles (Nielsen 2001) • Visibility of system status • Match between system and the real world • User control and freedom • Consistency and standards • Help users recognize, diagnose and recover from errors • Error prevention • Recognition rather than recall • Flexibility and efficiency of use • Aesthetic and minimalist design • Help and documentation
- 24. Key points • Interaction design is concerned with designing interactive products to support the way people communicate and interact in their everyday and working lives • It is concerned with how to create quality user experiences • It requires taking into account a number of interdependent factors, including context of use, type of activities, cultural differences, and user groups • It is multidisciplinary, involving many inputs from wide-reaching disciplines and fields