User Interface Design CIS Office hours: Tuesday 1-2pm Thursday 12-1pm Room St James

Lectures: 27 hours in total Revision next term Exam at the end of this academic year

Overview: First Lectures: Introduction. What is User Interface Design and Human Computer Interaction. Following Lectures: Human Aspects and Characteristics of Interaction.

Overview (continued): Middle of term: Design approaches. Later during term: Tools and techniques. End of term: Evaluation of user interface design.

Overview (continued): Also at end of term: Practical session where you have a chance to think in small groups how to design good user interfaces for particular purposes.

Literature: Jasna Kuljis User Interface Design CIS322 Course Booklet. Preece, Rogers, Sharp, Benyon, Holland & Carey (1994). Human Computer Interaction. Wokingham: Addison-Wesley.

What is User Interface Design? Many electronic devices are interactive systems, where users and the device interact through a User Interface (often through a Graphical User Interface). Examples: Both hardware and software for Desktop computers, Laptops, PDAs (=Personal Digital Assistants, handheld devices), Mobile Phones, DVD Players, MP3 Players, Electronic Wearables etc.

Electronic wearables, e.g. controlling audio players, healthcare (measuring heartrate, stress hormons, etc.)

For these devices to be accepted by the user, they must be effective and particularly well designed. User interface design is particularly important for wireless devices and these devices will become even more important in the future.

Various terms, one meaning Human Computer Interface (HCI) Human Computer Interaction (also HCI) Human Systems Interface (HSI) Computer Human Interaction (CHI) No agreed definition!

I will rely on the meanings adapted in Jasna Kuljis User Interface Design booklet. In this booklet, the meaning of Human Computer Interaction is broader and the meaning of User Interface Design is more specific.

User Interface Design: explicit design of the interface, by incorporating both software and hardware issues. However, some authors also consider User Interface Design within the overall system design framework, including social and organisational factors as well as evaluation of the system. This is what Jasna Kuljis refers to as Human Computer Interaction.

Purpose of Human Computer Interaction: 1. Analysis of what people need 2. Design of devices (at first: design of prototypes) 3. Evaluation whether users find them effective 4. Implementation and improvement of devices

Goals of Human Computer Interaction To improve the safety, utility, effectiveness, efficiency and usability of systems that include computers or related electronic devices.

Usability The degree to which specific users can achieve specific goals within an environment (Booth, 1989). Shackel (1991) suggests 4 usability criteria: 1.Effectiveness 2.Learnabililty 3.Flexibility 4.Attitude

Usability (continued) Shackel (1991) proposed to measure these criteria quantitatively. The criteria may be interrelated, i.e. better effectiveness can correlate with better learnability. Quantitative measurements tell about extent of usability, but do NOT tell how to improve the usability of a system (Booth, 1989). Qualitative information tells designers how to improve system.

Usability (continued) General Interface Usability Principles for Graphical User Interfaces (Molich & Nielsen, 1990) Simple dialogue in users language Minimise memory load Consistency Feedback Clearly marked exits Clever Shortcuts Good error messages Prevent Errors in the first place

Usability (continued) The General Interface Usability Principles (Molich & Nielsen, 1990) support the four identified usability dimensions by Shackel (1991): Effectiveness, Learnability, Flexibility and Positive User Attitude.

Different Users Adjusting design to specific needs of the users Different age groups of users Study of user behaviour, user abilities to interact with programs and devices etc.

Usability Defects Anything in the product that complicates completing the task: Unnecessary Navigation Poor Design or Layout Inappropriate Feedback (too little or too much) Poor Terminology (unclear words or abbreviations) Problems with Modality (e.g. when switching modes) Inconsequential Redundancies (e.g. repetitions) No Match with User Tasks (expectations unfulfilled) User has no trust in the system

How do we design good User Interfaces? (we will talk about this in greater detail at the end of the term) For now: combining technical and design knowledge with knowledge about human interests and capabilities and knowledge about social, organisational and physical aspects of users environment (e.g. work, spare time etc.).

Interdisciplinary Approach of Human Computer Interaction Computer Science Artificial Intelligence Visual Arts, Design and Media Studies Information Engineering Cognitive Psychology Social and Organisational Psychology Sociology and Linguistics Ergonomics and Human Factors