1 CP586 © Peter Lo 2003 Multimedia Communication Human Computer Interaction

CP586 © Peter Lo User Interface Those aspects of the system that a user comes in contact with. An input language for the user, an output language for the machine, and a protocol for interaction. Example: GUI OS : Microsoft Windows 95. GUI application : Microsoft Word 97. Line based OS :Unix, DOS. Banking: ATM, EFTPOS. Phone Banking: National Australia Bank, BPAY and Commonwealth. Other: Video recorder and a microwave.

CP586 © Peter Lo User Interface Design User interface design requires an understanding of Human-Computer Interaction (HCI) and user- centered design principles. The Human-Computer Interface is the part of the computer we actually see. Although the product may consist of millions of software and hardware components, the interface is the component that interacts with a user and allows us to achieve something with a given application.

CP586 © Peter Lo Human Computer Interaction A set of processes, dialogues, and actions through which a human user interacts with a computer. A discipline concerned with design, evaluation and implementation of interactive computing systems for human use. HCI design is the engineering process of designing interactive computer systems so that they are efficient, pleasing, easy to use and do what people want. Design of the human-computer interface is part of a wider subject area of HCI.

CP586 © Peter Lo Disciplines Contributing to HCI Computer Science. Cognitive, social and organisational Psychology. Ergonomic and Human Factors. Linguistics. Artificial Intelligence. Engineering and Design.

CP586 © Peter Lo The Goals of HCI To develop or improve the safety, utility, effectiveness, efficiency and useability of systems that include computers. Poor interfaces can lead to system failure or inefficient usage. A bad interface will cause the rejection of a system even though it may have an excellent internal software design.

CP586 © Peter Lo HCI specialists strive to : Understand the factors (psychological, ergonomic, organisational and social) that determine how to use computers effectively. Develop tools and techniques to help designers ensure that computer systems are suitable for their desired application. Achieve efficient, effective and safe interaction with computer systems.

CP586 © Peter Lo HCI and Multimedia When developing multimedia applications, HCI is extremely important. Output devices provide information and feedback in a form perceptible by a human. Multimedia interfaces must be designed to be easy to use, efficient, intuitive and effective.

CP586 © Peter Lo Gestalt Psychology The natural ability of a viewer to organise information into sensible groups. The ability to separate images into the figure and the background. The tendency for the eye to continue viewing in a line. The ability to perceive groups of objects according to their similarity.

CP586 © Peter Lo Cultural differences Beware of different significance of icons (eg symbol for mail box, hand gestures). Colours: white for mourning in Japan, red for Chinese weddings. Words: “trash”, “garbage”, “rubbish”. Cultural difference between programmers and users!!

CP586 © Peter Lo Metaphors and Principles Metaphor : The application of a word or phrase to an object or concept which it does not literally denote, in order to suggest comparison with another object or concept. It is often useful to use a metaphor to symbolise and simplify interaction between a user and a computer.

CP586 © Peter Lo Eight User-centered Design Principles 1.Understand the Underlying Business Functions 2.Maximize Graphical Effectiveness 3.Profile the System's Users 4.Think Like a User 5.Use Prototyping 6.Design a Comprehensive Interface 7.Continue the Feedback Process 8.Document the Interface Design

CP586 © Peter Lo Good User Interface Design Good user interface design is based on a combination of Ergonomics ( 人類工作學 ), Aesthetics ( 知覺 ), and Interface Technology. Ergonomics – How people work, learn and interact with computer. Aesthetics – How an interface attractive and easy to use. Interface Technology – Provide the operational structure for design objective.

CP586 © Peter Lo User Interface Design Guidelines Focus on Basic Objectives Build an Interface that is Easy to Learn and Use Provide Features that Promote Efficiency Make it Easy for Users to Obtain Help or Correct Errors Minimize Input Data Problems Provide Feedback to Users Create an Attractive Layout and Design Use Familiar Terms and Images

CP586 © Peter Lo User Interface Controls The designer can include many control features, such as Menu Bars, Toolbars, Dialog Boxes, Text Boxes, Toggle Buttons, List Boxes, Scroll Bars, Drop-down List Boxes, Option Buttons, Check Boxes, Command Buttons, Spin Bars, and Calendars among others.

CP586 © Peter Lo User Interface Controls

CP586 © Peter Lo Input Design Issues Data Capture is the identification and recording of source data. Data Entry is the process of converting source data into computer-readable form and entering it into the information system.

CP586 © Peter Lo Six Main Input Design Objectives 1. Select a suitable input and data entry method 2. Reduce input volume 3. Design attractive data entry screens 4. Use validation checks to reduce input errors 5. Design required source documents 6. Develop effective input controls