INTRODUCTION TO USER INTERFACE DESIGN P A R

INTRODUCTION TO USER INTERFACE DESIGN P A R T 3 DR JIHANE BOULAHIA DR SMIRANI LASSAAD

UID ISSUES üIncreasing population of computer system users üGrowing power of computers ü New interaction devices üExplosion of multimedia: sound, image, video etc. üDevelopment of computer networks DIGITAL CONVERGENCE

UID Multidisciplinary domain üComputer science § § § Artifial Intelligence Programming Speech synthesis and recognition Natural Langage Picture System ü Cognitive ergonomics, software ergonomics ü Communication, graphics, audiovisual ü Educational sciences, didactics ü Cognitive psychology ü Anthropology, sociology, philosophy, linguistics

ADAPT THE UID ü To the context • • general public (offer an immediate grip) leisure (make the product attractive) industry (increase productivity) critical systems (ensure zero risk) ü To the characteristics of the task repetitive, regular, occasional, sensitive to changes in the environment, constrained by time. . . ü To the Technical constraints Platform, memory size, screen, sensors, effectors old code reuse

DESIGN PRINCIPLES • User familiarity – The interface should be based on user-oriented terms and concepts rather than computer concepts. For example, an office system should use concepts such as letters, documents, folders etc. rather than directories, file identifiers, etc.

DESIGN PRINCIPLES • Minimal surprise – If a command operates in a known way, the user should be able to predict the operation of comparable commands

DESIGN PRINCIPLES • Consistency – The system should display an appropriate level of consistency. Commands and menus should have the same format, command punctuation should be similar, etc.

DESIGN PRINCIPLES • Recoverability – The system should provide some resilience to user errors and allow the user to recover from errors. This might include an undo facility, confirmation of destructive actions, 'soft' deletes, etc.

DESIGN PRINCIPLES • User guidance – Some user guidance such as help systems, on-line manuals, etc. should be supplied

DESIGN PRINCIPLES • User diversity – Interaction facilities for different types of user should be supported. For example, some users have seeing difficulties and so larger text should be available

USER-SYSTEM INTERACTION • Two problems must be addressed in interactive systems design – How should information from the user be provided to the computer system? – How should information from the computer system be presented to the user?

USER-SYSTEM INTERACTION • User interaction and information presentation may be integrated through a coherent framework such as a user interface metaphor