Gary MarsdenSlide 1University of Cape Town Human-Computer Interaction - 1 Gary Marsden ( ) July 2002

Gary MarsdenSlide 2University of Cape Town Why am I here?  Course objectives –Understand why HCI is important for software development –How HCI can be fitted in to software engineering practice –Programming interactive systems –Effective use of user modelling and evaluation techniques

Gary MarsdenSlide 3University of Cape Town Roadmap  Justification of HCI  Interaction styles and metaphors  Interface programming tools  System lifecycles  Task Analysis  User Modelling  Design Guides  Prototyping  Evaluation techniques

Gary MarsdenSlide 4University of Cape Town Resources  On-line – – –  Print –Interaction Design - Preece, Rogers & Sharp –Human-Computer Interaction - Dix, Finlay, Abowd & Beale

Gary MarsdenSlide 5University of Cape Town Goals of HCI  Develop usable products –Usability means easy to learn, effective to use and provide an enjoyable experience  Involve users in the design process  We will discuss why this is important in a later lecture

Gary MarsdenSlide 6University of Cape Town Key Elements  Psychology  Social Sciences  Computing Science  Engineering  Ergonomics  Informatics

Gary MarsdenSlide 7University of Cape Town Radios!

Gary MarsdenSlide 8University of Cape Town What else is frustrating  Paperclip 

Gary MarsdenSlide 9University of Cape Town Reasons  There are many reasons why people should improve interaction between humans can computers; we shall look at four –Business –Quality of Life –Safety –Standards

Gary MarsdenSlide 10University of Cape Town Business  Within business, investment must produce some financial return  Developing interfaces can be expensive –What is the return?

Gary MarsdenSlide 11University of Cape Town Productivity Paradox  Loosely, productivity is a measure of output for a given input configuration  Computers are supposed to enhance productivity by increasing efficiency  From 1950 to 1973, US industry showed such an increase  Since 1973, this has not been the case –A period of intense use of IT and PCs WHY?

Gary MarsdenSlide 12University of Cape Town Paradox?  Could be a spurious correlation  Landauer (1995), ex IBM, investigated –US productivity short by 1.5% (30 Billion USD) –IT investment return down by 13.3% (0f 225 billion) –This equates to 30 Billion USD –Aha!  Well, could be –“Can use statistics like a drunk man, for support rather than illumination”

Gary MarsdenSlide 13University of Cape Town Computerisation  What is clear is that IT investment was good (for productivity) but isn’t as good now –Formerly computerisation where manual tasks were replaced by computers E.g. Bank accounts –Now, computers are used to ‘augment’ (Information Technology) - not so good ATM’s, telephone ‘help’ systems –People now spend so long interacting with the IT system, they do not do their jobs Reason for paradox?

Gary MarsdenSlide 14University of Cape Town Computerisation

Gary MarsdenSlide 15University of Cape Town Deadlines  IT projects are notorious for being late –Temptation to ‘skip’ HCI stuff  Cooper argues that it is better to ship a good product late than a bad one early –Due to early-adopter mentality (most IT people are early adopters)  Palm Pilot was six years late! –Go, Newton, GM, Palm Pilot

Gary MarsdenSlide 16University of Cape Town Creeping Featurism  or “Second Systems Effect”  Not just bad from SE perspective  Confusing to user having to select options –Microsoft Word has about 105 menu options –I started using it in 1993 –The only ‘new’ feature I use is the wiggly red line

Gary MarsdenSlide 17University of Cape Town New Products  Current attitude of many companies is ‘throwing mud against the wall’ –To see what sticks  Keep releasing products until something works –If version 4.0 works, what about the poor people who bought ?  We need to bring users in to the design process –More later

Gary MarsdenSlide 18University of Cape Town Legal issues  Besides business considerations there are legal and ethical issues to interface design  EU has workplace safety directives for –Ergonomics: making sure chairs etc. conform to human physical form –90/270/EEC requires that employers when designing, selecting, commissioning or modifying software should ensure that: it is suitable for the task it is easy to use, and is adaptable it provides feedback, it displays information in format and at a pace suitable for the user it conforms to the ‘principles of software ergonomics’  This is law in many EU countries

Gary MarsdenSlide 19University of Cape Town Ethics  As developers, it is our responsibility to provide software our users can use  Users are not developers –Developers like puzzles / users do not  Developers are users –Leads them to expect all users are like them  Most researchers agree developers are to blame for hard-to-use systems –But the fault lies in the development methodologies as most developers are nice people

Gary MarsdenSlide 20University of Cape Town Safety Critical Systems  Productivity is one thing, but poor design in safety critical systems can have catastrophic results  To protect themselves, designers of bad systems blame ‘operator error’  Kegworth air disaster –47 killed, 74 injured due to ambiguous ‘engine fail’ light  Ralph Nader –Handbrake failures

Gary MarsdenSlide 21University of Cape Town Designer Error  Engineers build safety systems that perform to amazing levels of excellence  They then give these systems to operators who don’t know how to use them and have not be consulted in their design  Need to think more about the ‘system’ –Train users of safety critical systems as drivers are trained  We shall look at user models and training later

Gary MarsdenSlide 22University of Cape Town Discussion  Who is to blame here? –I step out on a road crossing with a car about 200 yards away heading towards me. The car’s ABS brake system fails, the driver tries to avoid me but strikes me. The car is a hire car. The ABS system on the car was developed by a subcontractor to the car manufacturer.

Gary MarsdenSlide 23University of Cape Town Standards  Before any legal requirement can be enforced, there needs to be a requirement  Usually called a standard –Developed by researchers & industry –Tries to be ‘non-partisan’ and include government and academics –Huge marketing potential –Standard must be adopted –If adopted, can become a purchase point  What standards are you aware of?

Gary MarsdenSlide 24University of Cape Town ISO standards  ISO standard 9241 describes in part specifying systems for usability. It gives the following definitions: –Usability: the effectiveness, efficiency and satisfaction with which specified users achieve specified goals in particular environments. –Effectiveness: The accuracy and completeness with which specified users can achieve specified goals in particular environments. –Efficiency: The resources expended in relation to the accuracy and completeness of goals achieved.  This is rare, as usability standards are hard to enforce –Software standards also rare - tends to be hardware standards

Gary MarsdenSlide 25University of Cape Town Who cares?  Having seen why HCI is important, how come things are hard to use –Dancing bear syndrome –Jigsaw puzzle guru –SE is immature –Arrogance stupid users or stupid software –Cognitive dissonance

Gary MarsdenSlide 26University of Cape Town Summary  From this unit, I hope that you have learnt: –IT is not a panacea –Programmers are good, but need better methodologies for incorporating users into design –Users should be considered a key part of safety- critical systems –Mechanisims exist (legal, standards etc.) to ensure that we do get good software  In this unit we have been looking only at problems –Cheer up, the rest of the course is about solutions!