1 multimedia design. 2 usability no matter how powerful or potentially useful a multimedia...
Post on 20-Dec-2015
215 Views
Preview:
TRANSCRIPT
2
Multimedia DesignMultimedia Design
UsabilityNo matter how powerful or potentially useful a
multimedia software application or web site design is, if it can not be worked by the intended user then it is worthless
Communication is at least as important as computation
4
Iterative DesignIterative Design
Evaluate with real users
Identify user needs or problems
Design a solution
Prototype the solution
5
Darn these hooves! I hit the wrong switch again! Who designed these instrument panels, racoons?
Multimedia DesignMultimedia Design
6
The Interactive CycleThe Interactive Cycle
Evaluates and understands the
display
Interprets input events to make
changes
Data model for the application information
Updates to the display
Formulates goals and actions,
generates inputs
Updates to the display
Data model changes
7
Gulfs of UnderstandingGulfs of Understanding
Don Norman has identified two gulfs in a user’s understanding that cause the interactive cycle to break downGulf of EvaluationGulf of Execution
8
Gulf of EvaluationGulf of Evaluation
Users must interpret what they see on the screen and evaluate it relative to their ultimate goals
There are many ways in which this evaluation might fail:Ergonomic –
• Text too small to read
• Text has poor contrast with background colour
12
Gulf of EvaluationGulf of Evaluation
Design and layout – • Items may be ineffectively grouped and so the
users misses an important relationship
• Critical information incorrectly placed
• All information may appear the same without emphasis or highlights
Relevant information must not only be on the screen, but in a form which is immediately obvious
15
Gulf of ExecutionGulf of Execution
This arises when the user does not know what sequence of input events will accomplish the desired goal
There are several things that might cause this gulfThe user does not know what the system can
doThe operation of objects on the screen are not
obvious e.g buttons, links, scroll bars etc.Inadequate feedback
19
Consistency and SimplicityConsistency and Simplicity
Be consistent in your use of:SizeColour LocationWordingFunctionSequencing
23
Human Memory IssuesHuman Memory Issues
7 items +/- 2
Short term memory is approx. 30 seconds to 2 minutes
User should not need to buffer information from one screen to the next
25
Human Memory IssuesHuman Memory Issues
Avoid stacking
Design for task closure
Recognition rather than recall
26
Status IndicatorsStatus Indicators
Whenever the system is performing a potentially lengthy process the user should be given feedback e.g status bar, hourglass, loading screen
System should have response time suitable for task
27
Design GuidelinesDesign Guidelines
General text format rules:Only use two levels of intensityUse underlining, bold, inverse video etc.
sparinglyUse no more than 3 different fontsSerif fonts are easier to read, but sans-serif
can look more modernCapitalise as you would in normal sentences
30
Design GuidelinesDesign Guidelines
Colour is perhaps the most overused feature in multimedia designsUse no more than 4 colours on a screenNo more than 7 in an applicationGenerally blue or black backgrounds with
white or yellow characters respectively give the best contrast, but not necessarily the best look!
Blue should not be used for text as it is one of the hardest colours to read
31
Design GuidelinesDesign Guidelines
Consider colour conventions carefullyRed: passion, romance, fire, violence, aggression. Red
means stop, warning or forbidden in many culturesPurple: creativity, mystery, royalty, mysticism, rarity,
associated with death in some culturesBlue: loyalty, security, conservatism, tranquillity,
coldness, sadnessGreen: nature, fertility, growth, envy, go, environmentYellow: brightness, illumination, illness, cowardice Black: power, sophistication, contemporary style,
death, morbidity, evilWhite: purity, innocence, cleanliness, truth, peace,
coldness, sterility
32
Colour HarmonyColour Harmony
One of the most challenging aspects of visual design is developing effective colour harmonies that strike a balance between monotony and over stimulation
34
Design GuidelinesDesign Guidelines
Sound:Use harsh and soft audio tones for warnings
and positive feed back respectivelySound can add to a site or application, but can
also be annoyingIt is always a good idea to provide the option
to turn the sound off
35
Display IssuesDisplay Issues
Maintain display inertiaStatic objects such as buttons, words and
icons that appear on many screens should always appear in the same location
Location, shape and size of objects should be kept as consistent as possible
36
Display IssuesDisplay Issues
Organise the screen to manage complexityEliminate unnecessary informationUse concise wording or easy to recognise
iconsUser performance suffers when less that 25%
of the screen is white space 50% white space is recommended for textual
displaysRelated information should be grouped
logically
top related