June 2010 Edition
Computer Science Department, University of Cape Town
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During the week you might have encountered a whole range of systems (mobile phones, cash machines, ticket machines, word-processors, the web etc) as you attempted to achieve a diverse set of goals (travelling from home to work, completing an assignment, finishing off your home accounts etc).
Some systems would have been usable and useful whilst others left you confused and frustrated. Some of the systems you might have used for the first time – what was your experience with these novel situations?
What would a human travel agent do if you tried to select an outward flight from one airport and a return flight to another?
They would probably draw your attention to the possible problems/ errors. So, the online system could bring up a warning message to highlight the possible unintentional booking you were about to make.
Sue’s characteristics might include:
Physical
Frailty – inability to press down on ordinary ‘hard’ buttons.
Wheelchair bound – ATM at wrong height.
Poor eyesight – difficulty in reading screen and legends on keyboard.
Mental
Memory problems – difficulties in remember PIN code and complicated sequences.
A redesigned ATM might include:
Large screen with large fonts for readability.
Large buttons with large legends. Easy to press.
Use of eye-based/ fingerprint-based validation to avoid need for PIN code.
One-to-two steps to get any transaction completed.
Speech synthesis options?
Speech recognition to avoid need for hand-based input? (what would the problems of using speech be?)
Some favourites amongst previous students include:
An interactive computer system is one which requires dynamic, frequent intervention by the user – online e-commerce sites, word-processors, ATM (cash machines) are all good examples.
Utility billing systems, bank cheque processing systems and direct mail letter printing systems are all examples of non-interactive system. These systems work repetitively through large amounts of data doing well defined and set tasks.
'Ubiquitous computing' is a term that looks to the future when computing systems will be deployed extensively within the environments we live and work within. Many people believe that these systems will be all around us, sensing events in the locality and providing us with effective, focused information and services any time any where.
A usable system is likely to be: learnable, flexible and robust. Users should be able to easily assess how they might use the system to achieve their goals and should be able to evaluate their progress as they use the system.
Your aim is to convince the board that spending money on HCI makes good business sense. Ways of doing this would include showing how HCI might reduce costs or generate incomes.
Could argue that by using HCI methods that products would improve such that:
Home users that bought the systems would be satisfied and feel good about their purchases. Their quality of life would be improved. This might lead to them buying further products in the future or recommending the company to their friends/ colleagues. Bad interfaces will lead to confusion which might mean that the company has to spend more on support (e.g. help lines or documentation).
Business users might find that the company becomes more productive – look again at the notes on productivity and HCI. This will lead to potential further sales.
If disasters/ fatalities occurred because of poor interfaces in the safety-critical systems, the company could be very seriously affected. It might be sued for high amounts of damage costs and its reputation would be greatly tarnished.
Summative evaluations occur once a system has been completely developed. In contrast, formative evaluations occur during development. Summative evaluations are required in two cases:
where a system has been developed in-house, a summative evaluation acts as a final check on usability and system acceptance. The system deployment should be delayed if problems are noted at this stage.
an organisation may need to decide between several possible bought-in (off-the-shelf) solutions. Summative evaluations can produce comparative information from a user point of view (e.g. which one is easier to learn, fits best with employees working practice etc).
Formative evaluations should be used whenever a system is being developed – these evaluations should help produce improved designs as the system evolves.
Psychologist – knowledge about the human capabilities and limitations in terms of information processing. How we perceive information (through our eyes, ears etc), focus our attention, use our memories, reason and problem solve.
Sociologist – knowledge about how people work and relate together. Particularly useful when designing the newer types of CSCW (computer support of collaborative work system).
Information system expert – various systems methodologies have been developed which attempt to involve users in the design process (e.g. Soft Systems Methodology).
Product designer – ergonomic aspects of the physical elements of the interactive system.
Computer scientist – knowledge about potential interaction technologies and methods; capabilities and limitations of the computer.