Hci Lect 02dad
Hci Lect 02dad
Hci Lect 02dad
the interaction
ergonomics
physical aspects of interfaces
industrial interfaces
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
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.
interaction styles
dialogue computer and user
distinct styles of interaction
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)
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
Query interfaces
Question/answer interfaces
user led through interaction via series of questions
suitable for novice users but restricted functionality
often used in information systems
Form-fills
Spreadsheets
first spreadsheet VISICALC, followed by
Lotus 1-2-3
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
WIMP Interface
Windows
Icons
Menus
Pointers
or windows, icons, mice, and pull-down menus!
minimal typing
flat buttons
click me!
3D workspaces
use for extra virtual space
light and occlusion give depth
distance effects
or sculptured
Windows
Areas of the screen that behave as if they
were independent
can contain text or graphics
can be moved or resized
can overlap and obscure each other, or can be laid
out next to one another (tiled)
scrollbars
allow the user to move the contents of the window
up and down or from side to side
title bars
describe the name of the window
Icons
small picture or image
represents some object in the interface
often a window or action
Pointers
important component
WIMP style relies on pointing and selecting things
Menus
Choice of operations or services offered on the screen
Required option selected with pointer
File
Edit
Options
Font
Typewriter
Screen
Times
Kinds of Menus
Menu Bar at top of screen (normally), menu
drags down
pull-down menu - mouse hold and drag down menu
drop-down menu - mouse click reveals menu
fall-down menus - mouse just moves over bar!
Menus extras
Cascading menus
hierarchical menu structure
menu selection opens new menu
and so in ad infinitum
Keyboard accelerators
key combinations - same effect as menu item
two kinds
active when menu open usually first letter
active when menu closed usually Ctrl + letter
Buttons
individual and isolated regions within a
display that can be selected to invoke
an action
Special kinds
radio buttons
set of mutually exclusive choices
check boxes
set of non-exclusive choices
Toolbars
long lines of icons
but what do they do?
fast access to common actions
often customizable:
choose which toolbars to see
choose what options are on it
Dialogue boxes
information windows that pop up to
inform of an important event or request
information.
e.g: when saving a file, a dialogue box is
displayed to allow the user to specify the
filename and location. Once the file is
saved, the box disappears.
interactivity
easy to focus on look
what about feel?
appearance + behaviour
Physical design
many constraints:
Design trade-offs
constraints are contradictory need trade-offs
within categories:
e.g. safety cooker controls
front panel safer for adult
rear panel safer for child
between categories
e.g. ergonomics vs. physical MiniDisc remote
ergonomics controls need to be bigger
physical no room!
solution multifunction controls & reduced functionality
Managing value
people use something
ONLY IF
it has perceived value
AND
value exceeds cost
BUT NOTE
exceptions (e.g. habit)
value NOT necessarily personal gain or money
Weighing up value
value
helps me get my work done
fun
good for others
cost
download time
money , $,
learning effort
General lesson
if you want someone to do something