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Usability and Accessibility Lecture 5 – 02/03/10. Heuristics as a design approach. Setting the scene. “Rehabilitation Robotics in Europe” c.1997 EU funded many projects under TIDE initiative LOTS of money!!! Projects generally major disasters Let’s see why ….
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Setting the scene • “Rehabilitation Robotics in Europe” c.1997 • EU funded many projects under TIDE initiative • LOTS of money!!! • Projects generally major disasters • Let’s see why…
EPI-RAID failed because… • No in-built market to sell to • Had to sell on its own merits • Too expensive • (~5000000DKK) • Overtaken by new technology • Internet • Not enough consideration of what it was to be used for • Too much focus on the technology Needed a user-centred design approach!
Question Can we use Nielsen’s heuristic in the design process? • i.e. not just for post-hoc testing
Reminder: The fundamental stages of design • STAGE 1 - define the problem • STAGE 2 - develop a solution • STAGE 3 - evaluate the solution user wants/needs system requirements develop a usable system for “all” users verify/validate for all users
The fundamentals of interaction • Card, Moran and Newell (1983 – “The Psychology of Human-Computer Interaction”) proposed that actions could be described by:
Putting heuristics into the design process 1 LEVEL 1 • STAGE 1 - Problem specification • STAGE 2a - Visibility of system status • PERCEPTION • STAGE 2b - Match between system and real world • COGNITION • STAGE 2c - User freedom and control • MOTOR FUNCTION • STAGE 3 - Evaluation/verification LEVEL 2 LEVEL 3 2 LEVEL 4 3 LEVEL 5 Also known as the 5-level model See Keates and Clarkson “Countering design exclusion”
Diagrammatically… From: Keates & Clarkson “Countering design exclusion”
The IRVIS (Interactive Robotic Visual Inspection System) prototype
Questions of interest • Question 1: Is the robot under-specified or fundamentally “wrong”? • Question 2: Can we make it usable? • Question 3: Can we make it accessible?
Level 1 - Problem requirements • AIM 1: What are the system requirements? • AIM 2: Why did the original interface fail? • ASSESSMENT: Verify problem definition
product specific potential objectives users requirements Level 1 – Understanding the system requirements • What are the system requirements? • Understand manual process • User observations • Why did the original interface fail?
Level 1 - Problem specification (cont.) • Inspection process requires: • Translation • Rotation • Tilting • Zooming • Focusing
Level 3 - User mental model – “Match between system and real world”
Level 5 - Social attributes • The design of a new interface has shown significantly increased usability • Qualitative user feedback extremely favourable • The final interface also showed improved usability for able-bodied users • Costly robot re-build avoided
Features of the 5-level model • Iterative approach, with user trials and evaluation at each level • Addresses each stage of the interaction process explicitly • Guidelines can be incorporated where applicable • Clear focus on usability
Improving the 5-level model… • Will be seen a little later…
Summary • Usability and design are closely intertwined • Usability needs to consider design perspectives • Usability methods used need to complement design process and stage of development lifecycle
What is a good/inclusive interface? • Acceptable by the intended user group Need to define: • What is the intendedusergroup? • What is acceptable?
Who are the intended users? Typical user stereotypes • The “disabled” • The “elderly” • The “personinthestreet” • The “customer”
Designing inclusively = design for the disabled (?) • Need to adopt inclusive design arises because user capabilities ≠ product demands • Thus users with limited or impaired capabilities need a more accessible version to be designed • User group most commonly (stereotypically) associated with limited or impaired capabilities is people with disabilities • Ergo – designing inclusively is really designing for the disabled
BOTTOM UP TOP DOWN Least capable Least capable Most capable Most capable Inclusive design philosophies
>€1500 <€100 Examples of the different approaches BOTTOM UP TOP DOWN AN Other Mouse
Approaches to “designing for the widest possible range of users” • Universal Design • Design for All • Universal Access • Inclusive Design • Countering Design Exclusion • Design for disability
Universal Design • For a long time the most famous “inclusive design” approach • Very popular in Japan and USA • Strong association with architectural design • Buildings access • Not big in Europe • “Guiding principles” seen as too rigid and too deeply associated with its US heritage
The 7 guiding principles of Universal Design • 1 - Equitable use • The design must be useful and marketable to people with diverse abilities • 2 - Flexibility in use • The design accommodates a wide range of individual preferences and abilities • 3 - Simple and intuitive • Use of the design is easy to understand, regardless of the user’s experience, knowledge, language skills or current concentration level • 4 - Perceptible information • The design communicates necessary information effectively to the user, regardless of the ambient conditions or the user’s sensory abilities
The 7 guiding principles of Universal Design • 5 –Tolerance for error • The design minimises hazards and the adverse consequences of accidental or unintended actions • 6 –Low physical effort • The design can be used efficiently and comfortably and with a minimum of fatigue • 7 –Size and space and approach for use • Appropriate size and space is provided for approach, reach, manipulation and use regardless of user’s body size, posture or mobility
Other approaches to designing for the most possible users • Design for All • An older approach, very popular at one time • Inclusive design • Popular in Europe • More flexible approach than Universal Design • Universal Access • “Inclusive design for HCI” • Countering design exclusion • Developed by Keates and Clarkson (see book of same name)
Design for All(?) • Synonymous with “one product for all” (note – incorrectly) • Not really a feasible goal (see first lecture) • EU eEurope initiative defines DfA as: • “…designing mainstream products and services to be accessible by as broad a range of users as possible.”
Defining “inclusive design” (source: Keates “Designing for accessibility”) • UK Department of Trade and Industry: • Inclusive design is a process whereby “…designers ensure that their products and services address the needs of the widest possible audience.” • RSA (Royal Society for the Encouragement of Arts, Manufacture and Commerce): • Inclusive design is “… about ensuring that environments, products, services and interfaces work for people of all ages and abilities.” • UK Design Council: • “Inclusive design is not a new genre of design, nor a separate specialism, but an approach to design in general and an element of business strategy that seeks to ensure that mainstream products, services and environments are accessible to the largest number of people.”
Countering design exclusion (CDE) • Defined in BS7000 Part 6: • Design exclusion is the “…inability to use a product, service or facility, most commonly because the needs of people who experience motor, sensory and cognitive impairments have not been taken into account during the design process.”
CDE philosophy • If you can identify who cannot use the product and why, then you know what to focus on fixing • More practical approach than “design for a wide variety of users (but we’re not going to tell you who and how many) in a wide variety of circumstances (ditto)”
Whole population Included population Excluded population What is exclusion? Increasing motion capability Increasing cognitive Increasing capability sensory capability
Where does design exclusion come from? “Designers design for themselves” Examples to follow… Design trade-offs…
SENSORY MOTION COGNITIVE How are people excluded? People are excluded based on their capabilities (DFS) • locomotion • hearing • reach and stretch • vision • dexterity • intellectual functioning • communication and the demands made by the product
Quantifying exclusion • We will look at how to measure and report exclusion in later lectures • You will see examples in the reading material for this week