1 Introduction Human-Computer Interaction. 2 Human-Computer Interaction: Aims Knowledge of HCI Some practical analysis and design skills Practical implementation.

  • Published on

  • View

  • Download


Slide 1 1 Introduction Human-Computer Interaction Slide 2 2 Human-Computer Interaction: Aims Knowledge of HCI Some practical analysis and design skills Practical implementation of GUIs Enable you to assess how HCI may be incorporated into software lifecycle Personal transferable skills Slide 3 3 Lecture Overview Background and aims of HCI Usability Rise in importance of Interactive Systems Graphical User Interface (GUI) Slide 4 Human Computer Interaction - HCI Association for Computing Machinery (ACM) defines human-computer interaction as "a discipline concerned with the design, evaluation and implementation of interactive computing systems for human use and with the study of major phenomena surrounding them. Slide 5 Goal of HCI Basic goal of HCI is to improve interactions between users and computers by making computers more usable and receptive to user's needs. Specifically, HCI is concerned with: methodologies and processes for designing interfaces (i.e., given a task and a class of users, design best possible interface within given constraints, optimising for a desired property such as learnability or efficiency of use) methods for implementing interfaces (e.g. software toolkits and libraries; efficient algorithms) techniques for evaluating and comparing interfaces developing new interfaces and interaction techniques developing descriptive and predictive models and theories of interaction Slide 6 6 Course Outline: HCI and the Software Lifecycle Problem statement Implementation U s e r P a r t i ci p a t i o n Definition Analysis Design User object modelling Requirements spec. (inc. usability specs.) Interaction design / Presentation design Systems Analysis (inc. user and task analysis) Evaluation (Analytical, Empirical) Users conceptual model design / Interaction style Prototype (inc. online help) System design spec. (inc. Interface design spec.) Slide 7 7 The Parts of User Interface Development Development of the User Interface Development of the interaction component Development of the interface software ConstructionalBehavioural Slide 8 Disciplines Contributing to Human Computer Interaction Computer Science Cognitive Psychology Artificial Intelligence Human Computer Interaction Graphic Design Sociology Ergonomics and Human Factors Slide 9 9 Central Aim and Approach of HCI Approach: User-Centred Users should not have to adapt to the interface: the interface should be intuitive and natural for them to learn and to use. Talking to users is not a luxury, its a necessity Aim: To optimise performance of human and computer together as a system Slide 10 10 User Centred Design Work PeopleTechnology Environment Slide 11 User-Centred Design (UCD) or Pervasive Usability is a design philosophy and a process in which needs, wants, and limitations of end users of a product are given extensive attention at each stage of design process. UCD can be characterized as multi-stage problem solving process that not only requires designers to analyse and foresee how users are likely to use a product, but also to test the validity of their assumptions with regards to user behaviour in real world tests with actual users. Chief difference from other product design philosophies is that UCD tries to optimise the product around how users can, want, or need to use the product, rather than forcing the users to change their behaviour to accommodate the product. Slide 12 User Centred Design Principles Early focus on users and tasks Structured and systematic information gathering (consistent across the board) Designers trained by experts before conducting data collection sessions Empirical Measurement and testing of product usage Focus on ease of learning and ease of use Testing of prototypes with actual users Iterative Design Product designed, modified and tested repeatedly. Allow for the complete overhaul and rethinking of design by early testing of conceptual models and design ideas. Slide 13 13 Software Quality (ISO 9126) FunctionalityFunctionality ReliabilityReliability UsabilityUsability EfficiencyEfficiency MaintainabilityMaintainability PortabilityPortability Slide 14 14 Requirements Gathering User Requirements Functional Data Usability Learnability Throughput Flexibility Attitude Slide 15 Usability Baileys Human Performance Model Slide 16 Usability For specified user and specified task Learnability Ease of learning User retention over time Throughput - High speed of user task performance Low user error rate Flexibility Freedom of object / action selection User expertise levels Attitude - subjective user satisfaction Slide 17 Participatory Design Paper Prototyping / Storyboarding Cognitive Walkthroughs Usability Testing Heuristic Evaluation Usability Testing Heuristic Evaluation Follow-up Studies Compare To Benchmarks Usability Testing Focus Groups Participatory Design Surveys Heuristic Evaluation Set Benchmarks Source: Based Upon Rubin, et al. Handbook of Usability Testing: How to Plan, Design, and Conduct Effective Tests Usability Testing Slide 18 When It Goes Wrong Rubin et. al. * have identified five reasons why products, especially technology focused ones, are typically hard to use. These are: Focus on the device or system during development Changing and adapting target audience Trivialising designing usable products Non-integrated working of specialist teams both internally and with each other Design and implementation does not always match. * Handbook of Usability Testing: How to Plan, Design, and Conduct Effective Tests by Rubin, Chisnell and Spool Slide 19 19 Microsoft and Quicken 1995 - Microsoft tries to purchase Quicken from Intuit for $1.5 billion Reason for attempted purchase: Quicken more usable than Microsofts own product Slide 20 20 Mitchell Kapor (Designer of Lotus 1-2-3 ) Quotes from A software Design Manifesto 1990 The lack of usability in software and the poor design of programs are the secret shame of the software industry. One of the main reasons most computer software is so abysmal is that its not designed at all, but merely engineered. ... implementors often place more emphasis on a programs internal construction than on its external design. (Reprinted in Bringing Design to Software, T. Winograd, 1996, Addison Wesley) Slide 21 21 Usability Transparency Relationship between users goals required actions results must be meaningful, not arbitrary Slide 22 22 Problems with ATMs Older people make much less use of ATMs 24 year olds : average 7 visits to an ATM per month Use drops off among those over 45 65+ years : two-thirds NEVER use an ATM Senior citizens often put off by ATMs because they find the machines complicated, inconvenient and intimidating. Buttons that didnt line up with commands Dimly lit screens hard to read in the glare of daylight Sometimes confusing menu choices Source: http://cnn.com/TECH/9712/04/t_t/atms.seniors/index.html Reporting on research by W. Rogers and A. Fisk, Georgia Institute of Technology Slide 23 23 Problems with ATMs (Continued) Researchers and banks expected ATMs to be intuitively easy to use Testing among senior citizens found only 20 percent correct operation For example, one man tried to withdraw $30. He entered the amount he wanted incorrectly because the directions -- calling for "multiples of 10" -- confused him Usability suggestions: Simpler on-screen instructions More "undo" buttons Banks should provide training for any customers who need it A "large percentage" of people they surveyed said they would use ATMs if trained Slide 24 24 Example: Lack of Transparency Old UU phones: Call Diversion Instructions Slide 25 25 Poor interface may cause: Increased mistakes in data entry and system operation Inaccessible functionality User frustration: low productivity and/or under utilisation System failure because of user rejection Nearly half of entire software development effort relates to the user interface. (Myers and Rosson, 1992) Slide 26 26 Rise in Importance of Usability Research machines1950sMathematiciansMachine reliability Scientistsusers do programming Scientistsusers do programming Mainframes1960sData-processingUsers of output (business & professionalsmanagers) grow 1970sdisenchanted with delays, 1970sdisenchanted with delays, costs and lack of flexibility costs and lack of flexibility Minicomputers1970sEngineering andUsers must still do must other non-computerprogramming; usability other non-computerprogramming; usability professionalsbecomes a problem professionalsbecomes a problem Microcomputers1980sAlmost anyoneUsability is the major problem problem Shackle, 1991 Slide 27 27 ENIAC 1943: Research Machine (U.S. Army Photo) Slide 28 28 IBM Mainframe 1960s (Photograph courtesy of the IBM archives) Slide 29 29 Minicomputers: 1970s and 1980s U.S. Army Photograph, courtesy of Michael John Muuss, Slide 30 30 Microcomputers: 1970s - 1990s Slide 31 31 Desktop & Multimedia Internet Ready PCs Towards Pervasive / Ubiquitous Computing: 2005 -... Slide 32 32 The Leading Trend in Software Rise of GUI. The pervasiveness of graphical user interfaces is a clear sign that all software of the future must address the users needs for ease of use. IEEE Software, Nov 1990 IEEE Software, Nov 1990 A very rich design medium Slide 33 33 Browser the New Graphical User Interface Slide 34 Windows 8 Pervasive Computing But Less Control 34 Slide 35 35 Benefits of GUIs over Text Interfaces User completes tasks faster Lower frustration e.g. Less modal operation Easy interleaving tasks Perceived lower fatigue Better able to self-teach - Reduced training costs Better able to learn more capabilities of applications Slide 36 Recommended Further Reading Slide 37 Gary Larson Slide 38 Advanced Common Sense SM http://www.sensible.com Recommended Further Reading Slide 39 39 Lecture Review HCI and other subject areas User-centred Usability Faster CPUs / bigger disks support highly interactive systems Interactive systems pervasive Benefits of GUIs


View more >