1. Human Computer Interaction Lecture 10 Interaction Paradigms

2. achieving goals within constraints
What is design?
achieving goals within constraints
goals - purpose
who is it for, why do they want it
constraints
materials, platforms, money
trade-offs

3. for Human–Computer Interaction
understand your materials
understand computers
limitations, capacities, tools, platforms
understand people
psychological, social aspects, human error
and their interaction …

4. To err is human Accident reports .. But … Human ‘error’ is normal
aircrash, industrial accident, hospital mistake
enquiry … blames … ‘human error’
But …
In fact not human error but human nature
concrete lintel breaks because too much weight
blame ‘lintel error’ ? … no – design error we 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!

5. The process of design what is wanted scenarios task analysis
interviews
Ethnography
(study of cultures)
what is there
vs.
what is wanted
guidelines
principles
dialogue notations
precise specification
architectures
documentation
help
evaluation
heuristics
scenarios task analysis
what is wanted
analysis
design
implement
and deploy
prototype

6. Requirements
what is there and what is wanted …
Analysis
ordering and understanding
Design
what to do and how to decide
Iteration and prototyping
getting it right … and finding what is really needed!
Implementation and deployment
making it and getting it out there

7. How to design with focus on users? know your user Personae (character)
User Focus Designing systems with focus on user is called User-Centred Design.
How to design with focus on users?
know your user
Personae (character)

8. Know your USER who are they? probably not like you! talk to them
Harder to answer if you are designing a generic software like word processor
probably not like you!
You assume your own interests and abilities
talk to them
Structured interviews, open-ended discussions
Bringing potential users fully into the design process - Participatory design

9. know your user watch them Talking with people might not be enough
Think about walking
Solution: watch and observe them either informally or involving them
Observations tell you what they do, they will tell you why

10. know your user use your imagination
Observing users can be costly … imagine their experiences

11. Persona
Picture of an imaginary person who represents your core user group
description of an ‘example’ user
not necessarily a real person
use as substitute user
what would Betty (as a Warehouse manager) think

12. Scenarios
stories for design
use and reuse

13. scenarios stories for design or stories of interaction linearity
Example of a short scenerio:
User intends to press the “save” button, but accidentally presses the “quit” button, so looses his work
communicate with others (Designers, users)
validate other models
understand dynamics (Behaviour of system not only screen shot)
linearity
time is linear - our lives are linear

14. Navigation Design Local structure – single screen(control)
Global structure – whole(system) site

15. From one screen looking out
Local Structure
From one screen looking out

16. Four golden rules knowing where you are knowing what you can do
knowing where you are going
or what will happen
knowing where you’ve been
or what you’ve done

17. Where you are – breadcrumbs
shows path through web site hierarchy
-Category, subcategory , this page

18. Design Focus- modes lock to prevent accidental use …
remove lock - ‘c’ + ‘yes’ to confirm
frequent practiced action
if lock forgotten
in pocket ‘yes’ gets pressed
goes to phone book
in phone book … ‘c’ – delete entry ‘yes’ – confirm … oops !

19. Global Structure
between screens within the application

20. Hierarchical Diagrams
the system
info and help
management
messages
add user
remove user

21. Network Diagrams main screen remove user confirm add user
show different paths through system

22. Levels of Interaction Widget choice Menus etc.
Form Elements, tag, links
Buttons, dials, lights
Screen design, Page design
Application navigation, Site Structure
Environment
other apps, O/S ,Web browser, The real world