Human Computer Interaction
An Introduction
Human-Computer Interaction
"Human-computer interaction (HCI) is the study of theinteraction between people, computers and tasks. It is principally concerned with understanding how people and computers can interactively carry out tasks, and how such interactive systems are designed."
Peter Johnson (1992)
"... even the hugest telescope has to have an eye-piece no larger than the human eye." Ludwig Wittgenstein
HCI – What is it all about?
users tasks
software/hardware environment
?
Pandora's Box?
linguistics
comp.science
sociology
psychology
ergonomics
?
philosophy
art
What is the problem?
Have you ever bumped into a door because you pulled instead of pushed?
Have you ever switched the wrong lights on or off? Have you ever made a mistake in programming your
video recorder? Have you ever taken hours to figure out to do exactly
what you want with a certain computer program? Have you ever left a web page because you could not
find what you were looking for?
The frustrations of everyday life
What is a 'User Interface'?
• It is the interface between the user and the computer...
... but it is more than just simple input and output.
• We must consider COGNITIVE ASPECTS of human ...
... and of course, everybody is different ...
• We must accept cognitive diversity, even though it makes the user interface design process more difficult!!
The interpretation of information from the outside world that is received through the senses.
Perception of objects and events and interpretation of them.
The wrong interpretation could be costly, inefficient, unpleasant, dangerous, and even fatal…
Example?
Cognition
Goals of interaction design
Develop usable productsUsability means easy to learn, effective to use
and provide an enjoyable experience Involve users in the design process
What to design?
Need to take into account Who the users are What activities are being carried out Where the interaction is taking place
Need to optimize the interactions users have with a product Such that they match the users activities and needs
for Human–Computer Interaction
understand your materials
understand computers limitations, capacities, tools, platforms
understand people psychological, social aspects human error
and their interaction …
To err is human
accident reports .. aircrash, industrial accident, hospital mistake enquiry … blames … ‘human error’
but … concrete lintel breaks because too much weight blame ‘lintel error’ ?
… no – design errorwe know how concrete behaves under stress
human ‘error’ is normal we know how users behave under stress so design for it!
treat the user at least as well as physical materials!
Logical or ambiguous design?
Where do you plug the mouse?
Where do you plug the keyboard?
top or bottom connector?
Do the colour coded icons help?
From: www.baddesigns.com
How to design them more logically
A provides direct adjacent mapping between icon and connector
B provides colour coding to associate the connectors with the labels
From: www.baddesigns.com
Task 2: (10 min)
• Design a stove top with four rings and four controls, one for each ring.
You are not allowed to use any labelling to indicate which knob applies to which ring.
A B C D
Which controls go with which rings (burners)?
Why is this a better design?
Discuss:
Mapping – The relationship between two things.
e.g. Turn steering wheel right, car turns right
Why is this a poor mapping of control buttons?
Task: Group work (15 min)
Design an interface for a small programme that converts between currencies.
Draw a design for the input / output screen.
The system can accept input by using a mouse, other pointing device or touch screen NOT by using a keyboard.
The programme must be able convert between BP, US dollars, Au Dollars , euros and Yen.
Note: You don’t have to actually carry out the calculations (just pretend)
www.baddesigns.com
Your task
Look at the following slide show of HCI devices. Form groups: Design a new interface for a common device: ensure you
have adhered to some of the laws in the quiz below Produce a quick slide show to present your work and
reasoning to the class
www.baddesigns.com
http://www.asktog.com/columns/022DesignedToGiveFitts.html