why is it challenging to design interactive system?
have to think about both usability and functionality there are different contexts that a system may be in
what are the 3 components that make up system context?
safety performance satisfaction
each weighted differently depending on the context
what is the context for high-risk domains?
high safety low performance low satisfaction
what is the context for workplace systems?
high safety high performance low satisfaction
what is the context for cuonsumer products?
high safety low performance high satisfaction
what do we ned to consider when designing interactive systems?
empathy for user anticipate the view of the user motivations actions to complete the task the context (eg. consumer? focus on satisfaction)
why is achieving good design hard?
hard for designers to be objective since they know so much about their product already focus too much on functionality which may not be what the consumer wants subjective and dependant on the content
what an we do to achieve good design?
follow design principles evaluate and test
what are design principles?
guidelines to assist the thought process when designing
what are design principles based on?
theory (cognitive science/ understanding human though processes) common sense experience (consultancy)
What are the 5 main design principles?
visibility feedback constraints consistency affordance
what is visibility?
the more visible a function the more likely the user will use it + use easily and correctly
what is an example of visibility?
(eg. controls for a car - horn) sensor technology (taps with sensors) are hard for people to learn to control as sensors hard to see
what is feedback?
give feedback about the action a user takes lets them continue the activity, make them awake of mistakes, correct their mistakes feedback can help visibility
what is an example of feedback?
audio (haptics and haptic sounds) tactile, verbal, visual, combination of feedback error messages with clear instruction (check connectivity) vs just a 404 error code
what is contraints?
determine/ restrict user interactions at given time con: can constrain a users interpretation of a problem
what is an example of constraints?
eg. GUI to deactivate certain menu options by grey them out
can be ambiguous (click something by mistake causing things to grey out) USB designed to only go in one way - physical constraint
what is consistency?
interfaces with similar elements and components for achieving similar tasks - follows rules
easier to learn, use, apply to simple designs harder to apply for complex designs (word processor that goes through refinement)
what is an example of consistency?
eg. colour scheme for a site, same type of buttons on a physical device
what is affordance?
attributes of an object that allows people to know how to use it (gives clue) - designed to be intuitive
designers must create objects that conform to user needs based on physical and perceptual capabilities, goals and past experience
what is an example of affordance?
eg. mouse invites clicking, computer recycle bin - integrates past experience of real life, buttons to turn light on or off, a handle on a teapot
what other design principles can be considered?
simplicity/ functional minimum cognitive engagement perceivability learnability mapping
what is simplicity/ functional minimalism?
functionally simplistic - simple things more likely to be used, task focused per page rather than overload on one page
what is cognitive?
reduce cognitive load (eg. too much info in one setting to process) to understand application
what is engagement?
developed to be interactive, happiness to interact, linking to feedback but on emotional level
what is perceivability?
affordability, interactive media engagement on a media basis
what is learnability?
interactions easy to learn and remember, link to simplicity and cognitive load
what is mapping?
process that narrows gap between user/ customers' needs and the product - eg. knobs on buttons map to each hob, screen gestures match what our hands are doing (scroll up and down using touchpad)
what happens as a result of applying design principles?
trade-offs
what are trade-offs?
balancing conflicting requirements, dependant on the purpose of the system not every design principle useful to the concept being designed
what are examples of trade-offs?
eg. multiple types of knives instead of consistent array of knives too much constraint limits visibility affordance can make interface cluttered
what is accessible design?
made to target a specific group but does not reach everyone the same targets those with disability
what is universal design?
accessible to all - disability or not
how is accessible design related to universal design?
a design can work for one target group (accessible design) but doesn't mean that everyone can use (universal design)
what is accessible and universal design based on?
affordance and context
what is the accessible design dilemma?
accessible design can restrict creativity or be complex
how do we create accessible design?
add video captions, transcriptions, always an alternative description to the original content structural mark up logically organised content with headings - headings create affordance as users read headings before text provide feedback text
what is alternative text (alt text)?
auto displayed when images don't load - alt text included on each element under 150 characters
who is alt text used by?
some people who rely on assistive technology (screen-readers) can't perceive information in images without a text or audio alternative
blind cognitive disability rely on assistive tech slow internet search engines
what makes good alt text?
Is brief Depends on the image context Describes the content and function of the image Should not be redundant or provide same information as the text Do not use phrases like "image of" or "picture of" Decorative images still need text
what are the main principles of accessibility?
80% accessibility issues based on blindness tag hamburg menus so screen readers don't skip them place important content in view of user test for accessibility with real uses - not personals enable zoom on mobile interface accessibility cheaper done upfront be aware of visual bias - good design check mobile accessibility separately aim for universal design