1. ISDE J T Burns September20111 Interactive Systems Design & Evaluation : John T Burns e-mail jtb@dmu.ac.ukjtb@dmu.ac.uk Mandatory Text User Interface design and Evaluation Debbie Stone et al Morgan Kaufman 2005 Recommended Text : Interaction Design Beyond HCI Preece Rodgers et al 2 nd Ed 2007 User Centred Wed Design, McCracken & Wolfe Pearson Prentice Hall, 2004 Human Computer Interaction Smith – Atakan Pub Thomson 2006

2. ISDE J T Burns September20112 Objectives of this Lecture To outline what we mean by ISDE To define HCI To demonstrate the need for ISDE To indicate the scope of ISDE To consider some general principles of HCI design

3. ISDE J T Burns September20113 What is ISDE about? Interactive systems are designed to enable communication between the system and the user This takes place via the systems ‘user interface’ ISDE is concerned with:- Designing interactive systems to support human activities Applying usability engineering techniques to evaluate the effectiveness and appropriateness of the design

4. ISDE J T Burns September20114 Goals of interaction design Develop usable products Usability means easy to learn, effective to use and provide an enjoyable experience Involve users in the design process

5. ISDE J T Burns September20115 Some Interactive Devices

6. ISDE J T Burns September20116 Some definitions – From HCI - ID Human-Computer Interaction a discipline concerned with the design, evaluation and implementation of interactive computing systems for human use and with the study of the major phenomena surrounding them Interaction design The design of spaces for human communication and interaction User Interface any boundary between the human user and the computer system (includes documentation and training material) not restricted to screens, keyboards and mice

7. ISDE J T Burns September20117 What is HCI HCI is concerned about :- Finding out how people use computers Trying to ensure that systems are designed to closely match users’ needs Ensuring that users can make sense of the information that is presented to them Ensuring that the user can communicate/interact with the system This is not always the case!!

8. ISDE J T Burns September20118 Getting it wrong! Some examples of bad design The Dishwasher The Vending Machine The ATM

9. ISDE J T Burns September20119 The dishwasher What is wrong with this display message? Error2

10. ISDE J T Burns September201110 Why is this vending machine so bad? Need to push button first to activate reader Normally insert bill first before making selection Contravenes well known convention From: www.baddesigns.com

11. ISDE J T Burns September201111 ATM

12. ISDE J T Burns September201112

13. ISDE J T Burns September201113 Getting it right! These illustrate 3 key factors that the designer needs to focus on The user The task The environment Next slide shows other factors

14. ISDE J T Burns September201114 Organisational Factors Environmental Factors Task Factors The User Health and Safety Factors Constraints Comfort Factors System Functionality Productivity Factors User Interface

15. ISDE J T Burns September201115 What is involved in the process of interaction design Identify needs and establish requirements Develop alternative designs Build interactive prototypes that can be communicated and assessed Evaluate what is being built throughout the process

16. ISDE J T Burns September201116 Core characteristics of interaction design users should be involved through the development of the project specific usability and user experience goals need to be identified, clearly documented and agreed at the beginning of the project iteration is needed through the core activities

17. ISDE J T Burns September201117 Introduction to ISDE – Part 2 Objectives To outline general design principles Justifying the need for good design To identify features of good design To consider design implications

18. ISDE J T Burns September201118 Design principles Wide range of design principles- guidelines or heuristics Provide list of 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 Design is complex not simply ticking checklist! Great skill is required

19. Design Goals Interactive designers aim to achieve the following Safe secure design Utility Effectiveness Efficiency Usability Appeal They also apply & use general design principles ISDE J T Burns September201119

20. ISDE J T Burns September201120 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

21. ISDE J T Burns September201121 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

22. ISDE J T Burns September201122 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”

23. ISDE J T Burns September201123 Constraints Restricting the possible actions that can be performed Helps prevent user from selecting incorrect options Three main types (Norman, 1999) physical cultural logical

24. ISDE J T Burns September201124 Physical constraints Refer to the way physical objects restrict the movement of things E.g. only one way you can insert a key into a lock How many ways can you insert a CD or DVD disk into a computer? How physically constraining is this action? How does it differ from the insertion of a floppy disk into a computer? Often used where safety is an issue – examples?

25. ISDE J T Burns September201125 Logical constraints Exploits people’s everyday common sense reasoning about the way the world works An example is the logical relationship between physical layout of a device and the way it works as the next slide illustrates

26. ISDE J T Burns September201126 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

27. ISDE J T Burns September201127 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

28. ISDE J T Burns September201128 Cultural constraints Learned arbitrary conventions like red triangles for warning Can be universal or culturally specific

29. ISDE J T Burns September201129 Universal Can you think of some icons for the following Restaurants Banks Garage/Services

30. ISDE J T Burns September201130 Mapping Relationship between controls and their movements and the results in the world Why is this a poor mapping of control buttons?

31. ISDE J T Burns September201131 Mapping Why is this a better mapping? The control buttons are mapped better onto the sequence of actions of fast rewind, rewind, play and fast forward

32. ISDE J T Burns September201132 Activity on mappings Which controls go with which rings (burners)? ABCD

33. ISDE J T Burns September201133 Why is this a better design?

34. ISDE J T Burns September201134 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

35. ISDE J T Burns September201135 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

36. ISDE J T Burns September201136 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

37. ISDE J T Burns September201137 Keypad numbers layout A case of external inconsistency 12 3 456 7 89 7 89 12 3 456 0 0 (a) phones, remote controls(b) calculators, computer keypads

38. ISDE J T Burns September201138 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 popularized in interaction design to discuss how to design interface objects E.g. scrollbars to afford moving up and down, icons to afford clicking on

39. ISDE J T Burns September201139 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 conceptualised as ‘perceived’ affordances Learned conventions of arbitrary mappings between action and effect at the interface Some mappings are better than others

40. ISDE J T Burns September201140 Justifying HCI Poor interface design can lead to Increased errors User frustration Poor system performance User rejection - particularly true for WWW

41. ISDE J T Burns September201141 Justifying HCI Good Interface design will provide Fail-safe systems Competitive advantages Financial rewards Increased efficiency User satisfaction and enjoyment

42. ISDE J T Burns September201142 What makes for a good interface? A good interface will Provide feedback Provide easy reversal of actions (relieves anxiety) Give users feeling that they are in control Reduce reliance on STM

43. ISDE J T Burns September201143 Think about a car... how much knowledge about a car do you need to be able to drive it? do the best designed cars give the driver the most information about the engine, suspension, etc? good design of the interface to the car includes designing controls that are obvious to use behave in the way you expect give fast feedback are comfortable to use hide unnecessary information from the user

44. ISDE J T Burns September201144 Perspectives on design users are often not interested in the program and use it only as a tool to achieve some task in their work give me £20 from my current account (ATM) draw me a section of the valve called P1023 in a place I can define (CAD system) manufacturers are aware of the importance of usability...... but often do not know how to design for usability and how to test or evaluate it effectively

45. ISDE J T Burns September201145 Continued perspectives... think ‘design first, implementation second’ design the interface first for usability, only compromise in the design for ease of implementation later if necessary think how the system and interface should support what the user wants to do, rather than what the system is capable of doing

46. ISDE J T Burns September201146 Misconceptions about user interface design a usable system has lots of functions ‘I know it’s a bit hard to use but it’s all described in the Help system’ ‘I know it works - I’ve got the people in the office (or on the course) to use it’ I tested it and everything worked so I know the interface is good

47. ISDE J T Burns September201147 User Centred Design all systems need not be designed to suit everyone....... but should be designed around the needs and capabilities of those people who will use them usability - concerned with making systems easy to learn, easy to use and efficient to use

48. ISDE J T Burns September201148 Implications for the design process there must be an early focus on users and tasks there must be a clear understanding of what particular usability attributes are important to ensure usability targets can be met, there must be testing of prototypes of the design from an early stage in the process results from prototype testing need to be used to modify the design and this is then retested - i.e. there are iterations in the design - test cycle software tools are needed to support this process - to enable designs to be built and modified with little programming overhead

49. ISDE J T Burns September201149 Design Methods There is no single ‘golden’ design method that can ensure successful interactive design Requires designer to gain an understanding of the problem and apply appropriate techniques Fundamental to achieving success is the need to shift continually between two types of design activity

50. ISDE J T Burns September201150 Design Activities Analysis During analysis we test the design to ensure it is meeting our targets for usability and quality Synthesis Here we shape the design drawing on fresh ideas, previous experience and solutions to similar problems

51. ISDE J T Burns September201151 Key points ID involves taking into account a number of interdependent factors including context of use, type of task and kind of user Need to strive for usability and user experience goals Design and usability principles are useful heuristics for analyzing and evaluating interactive products

52. ISDE J T Burns September201152 Further Reading The Psychology of Everyday things. Norman D 1988 Turn Signals are the Facial expressions of Automobiles. Norman 1992. Both books provide amusing and thought provoking examples of bad designs in everyday life. He uses this as the basis to argue for the need for technology to be humanized. www.bad-designs.com