1. IAS2223: Human Computer Interaction
Chapter 1: The Interaction

2. Content Model of interaction. Ergonomics. Interaction styles.
Interactivity.
The process of design.
Navigation design.
Screen design and layout.
Iteration and prototyping.

3. The Interaction
Address the translation between what the user wants and what system does – use interaction models
Ergonomics looks at physical characteristics of the interaction
Dialog between user and system
Takes place within a social and organizational context – affects both user and system

4. What is it?
Communication
user system
but is that all … ?

5. Interaction terms domain – the area of work under study
e.g. graphic design
goal – what you want to achieve
e.g. create a solid red triangle
task – how you go about doing it – ultimately in terms of operations or actions
e.g. … select fill tool, click over triangle
Note …
traditional interaction …
use of terms differs a lot especially task/goal !!!

6. Model of Interaction

7. Donald Norman’s Model Seven stages
user establishes the goal
formulates intention
specifies action sequence
executes action
perceives system state
interprets system state
evaluates system state with respect to goal
Norman’s model concentrates on user’s view of the interface

8. Execution/evaluation loop
system
evaluation
execution
goal
user establishes the goal
formulates intention
specifies actions at interface
executes action
perceives system state
interprets system state
evaluates system state with respect to goal

9. … cont’d system evaluation execution goal user establishes the goal
formulates intention
specifies actions at interface
executes action
perceives system state
interprets system state
evaluates system state with respect to goal

10. … cont’d system evaluation execution goal user establishes the goal
formulates intention
specifies actions at interface
executes action
perceives system state
interprets system state
evaluates system state with respect to goal

11. … cont’d system evaluation execution goal user establishes the goal
formulates intention
specifies actions at interface
executes action
perceives system state
interprets system state
evaluates system state with respect to goal

12. Human Errors – slips and mistakes
understand system and goal
correct formulation of action
incorrect action
mistake
may not even have right goal!
Fixing things?
slip – better interface design
mistake – better understanding of system

13. Abowd and Beale framework
extension of Norman…
their interaction framework has 4 parts
user
input
system
output
each has its own unique language interaction  translation between languages
problems in interaction = problems in translation S
core U
task O
output I
input

14. Study of the physical characteristics of interaction
Ergonomics
Study of the physical characteristics of interaction
Also known as human factors – but this can also be used to mean much of HCI!
Ergonomics good at defining standards and guidelines for constraining the way we design certain aspects of systems

15. Ergonomics - examples arrangement of controls and displays
e.g. controls grouped according to function or frequency of use, or sequentially
surrounding environment
e.g. seating arrangements adaptable to cope with all sizes of user
health issues
e.g. physical position, environmental conditions (temperature, humidity), lighting, noise,
use of colour
e.g. use of red for warning, green for okay, awareness of colour-blindness etc.

16. Interaction styles command line interface menus natural language
question/answer and query dialogue
form-fills and spreadsheets
WIMP
point and click
three–dimensional interfaces

17. Command line interface
Way of expressing instructions to the computer directly
function keys, single characters, short abbreviations, whole words, or a combination
suitable for repetitive tasks
better for expert users than novices
offers direct access to system functionality
command names/abbreviations should be meaningful!
Typical example: the Unix system, DOS

18. Menus Set of options displayed on the screen Options visible
less recall - easier to use
rely on recognition so names should be meaningful
Selection by:
numbers, letters, arrow keys, mouse
combination (e.g. mouse plus accelerators)
Often options hierarchically grouped
sensible grouping is needed
Restricted form of full WIMP system

19. speech recognition or typed natural language
Familiar to user
speech recognition or typed natural language
Problems
vague
ambiguous
hard to do well!
Solutions
try to understand a subset
pick on key words

20. Query interfaces Question/answer interfaces Query languages (e.g. SQL)
user led through interaction via series of questions
suitable for novice users but restricted functionality
often used in information systems
Query languages (e.g. SQL)
used to retrieve information from database
requires understanding of database structure and language syntax, hence requires some expertise

21. Form-fills Primarily for data entry or data retrieval
Screen like paper form.
Data put in relevant place
Requires
good design
obvious correction facilities

22. sophisticated variation of form-filling.
Spreadsheets
first spreadsheet VISICALC, followed by Lotus MS Excel most common today
sophisticated variation of form-filling.
grid of cells contain a value or a formula
formula can involve values of other cells e.g. sum of all cells in this column
user can enter and alter data spreadsheet maintains consistency

23. … or windows, icons, mice, and pull-down menus!
WIMP Interface
Windows
Icons
Menus
Pointers
… or windows, icons, mice, and pull-down menus!
default style for majority of interactive computer systems, especially PCs and desktop machines

24. Point and click interfaces
used in ..
multimedia
web browsers
hypertext
just click something!
icons, text links or location on map

25. Three dimensional interfaces
virtual reality
‘ordinary’ window systems
highlighting
visual affordance
indiscriminate use just confusing!
3D workspaces
use for extra virtual space
light and occlusion give depth
distance effects
flat buttons …
… or sculptured
click me!

26. Elements of WIMP Windows Icons Menus Pointers Buttons Palettes
Toolbars
Dialog boxes

27. Context Interaction affected by social and organizational context
other people
desire to impress, competition, fear of failure
motivation
fear, allegiance, ambition, self-satisfaction
inadequate systems
cause frustration and lack of motivation

28. Interactivity design interactions not just interfaces
not just the immediate interaction
e.g. stapler in office – technology changes interaction style
manual: write, print, staple, write, print, staple, …
electric: write, print, write, print, …, staple

29. The process of design scenarios task analysis what is wanted
interviews
ethnography
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

30. Steps … requirements analysis design iteration and prototyping
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

31. … but how can I do it all ! !   limited time  design trade-off
usability?
finding problems and fixing them?
deciding what to fix?
a perfect system is badly designed
too good  too much effort in design  

32. local structure – single screen global structure – whole site
navigation design
the systems
info and help
management
messages
add user
remove user
local structure – single screen
global structure – whole site
start
main
screen
remove
user
confirm
add user

33. Interact at several levels:
widget choice
menus, buttons etc.
screen design
application navigation design
environment
other apps, O/S

34. think about structure within a screen local global wider still
later ...
local
looking from this screen out
global
structure of site, movement between screens
wider still
relationship with other applications

35. screen design and layout
Dix , Alan
Finlay, Janet
Abowd, Gregory
Beale, Russell 
screen design and layout
basic principles
grouping, structure, order
alignment
use of white space
ABCDEFGHIJKLM
NOPQRSTUVWXYZ

36. basic principles ask think design what is the user doing?
what information, comparisons, order
design
form follows function

37. available tools for layout
grouping of items
order of items
decoration - fonts, boxes etc.
alignment of items
white space between items

38. grouping and structure
logically together  physically together
Billing details:
Name
Address: …
Credit card no
Delivery details:
Delivery time
Order details:
item quantity cost/item cost
size 10 screws (boxes)
…… … … …

39. decoration use boxes to group logical items
use fonts for emphasis, headings
but not too many!!
ABCDEFGHIJKLM
NOPQRSTUVWXYZ

40. alignment - text you read from left to right (English and European)
 align left hand side
boring but
readable!
Willy Wonka and the Chocolate Factory
Winston Churchill - A Biography
Wizard of Oz
Xena - Warrior Princess
Willy Wonka and the Chocolate Factory
Winston Churchill - A Biography
Wizard of Oz
Xena - Warrior Princess
fine for special effects but hard to scan

41. Usually scanning for surnames  make it easy!
alignment - names
Usually scanning for surnames  make it easy!  
Alan Dix
Janet Finlay
Gregory Abowd
Russell Beale
Dix , Alan
Finlay, Janet
Abowd, Gregory
Beale, Russell 
Alan Dix
Janet Finlay
Gregory Abowd
Russell Beale

42. alignment - numbers
think purpose!
which is biggest?

43. alignment - numbers
visually:
long number = big number
align decimal points
or right align integers

44. multiple columns
scanning across gaps hard: (often hard to avoid with large data base fields)
sherbert 75 toffee 120 chocolate 35 fruit gums 27 coconut dreams 85

45. multiple columns - 2 use leaders
sherbert 75 toffee 120 chocolate 35 fruit gums 27 coconut dreams 85

46. or greying (vertical too)
multiple columns - 3
or greying (vertical too)
sherbert 75 toffee 120 chocolate 35 fruit gums 27 coconut dreams 85

47. or even (with care!) ‘bad’ alignment
multiple columns - 4
or even (with care!) ‘bad’ alignment
sherbert 75 toffee 120 chocolate 35 fruit gums 27 coconut dreams 85

48. white space - the counter
WHAT YOU SEE

49. white space - the counter
WHAT YOU SEE
THE GAPS BETWEEN

50. space to separate

51. space to structure

52. space to highlight

53. physical controls grouping of items defrost settings type of food
time to cook
defrost settings
type of food
time to cook

54. physical controls grouping of items order of items type of heating
temperature
time to cook
start 1
1) type of heating 2
2) temperature 3
3) time to cook 4
4) start

55. physical controls grouping of items order of items decoration
different colours for different functions
lines around related buttons
different colours for different functions
lines around related buttons (temp up/down)

56. physical controls grouping of items order of items decoration
alignment
centered text in buttons ? easy to scan ?
centred text in buttons
? easy to scan ?

57. physical controls grouping of items order of items decoration
alignment
white space
gaps to aid grouping
gaps to aid grouping

58. Prototyping System with limited functionality
Prototyping help in easing the design

59. Thanks To tolerate someone else’s mistakes is one thing.
To forgive them is even greater.
Thanks