Unit 7: User-Centered Design (HL)

• User-centred design (UCD)


  The fundamental principle is that understanding the needs of the users is the key to designing the best products and services
• UCD


  • A designer must consider the needs, wants and limitations of the end user within every element of the design cycle
  • The ability to identify how users will interact with a product, service or system is vital for its success
  • Designers must be able to acquire and analyse valid data without making assumptions about how the product may be used
• The foundation of UCD is that good design requires that the needs and capabilities of the users are determined and incorporated into the design process from the start through to the finish
• Advantages of UCD


  • UCD design is to put yourself in the user's shoes
  • The design would be more intuitive
• Disadvantages of UCD


  • User-centric design is expensive
  • Difficulty to translate certain types of data into design
  • Products takes more time
  • Item may be too complicated and specific for public use leading to becoming more expensive
• The product must address the whole user experience


  Design should make it easy for the user to: determine actions possible at any time, see the options and results of actions, determine current system state, follow intuitively from intention to action
• User


  The person utilising the product. The person who is being affected by the product or who is reaping the benefits or drawbacks of the product. A product can alter as well, depending on the user
• Task


  The thing the product is supposed to do... The user may have multiple uses for the same product
• Environment


  The place where the product is likely to be used- indoors/outdoors, urban/rural, on Earth/in space etc.
• Iterative Design


  Iteration is the act of repeating a process with the aim of approaching a desired goal, target or result. Regular feedback from user would assist in making small changes to the product/design. Each repetition of the process is also called an "iteration", and the results of one iteration are used as the starting point for the next iteration
• The process is iterative, led by the user and developed through user-centred evaluation
• Principles of iterative design (ISO)


  • The design is based upon an explicit understanding of users, tasks and environments
  • Users are involved throughout design and development
  • The design is driven and refined by user-centered evaluation
  • The process is iterative
  • The design addresses the whole user experience
  • The design team includes multidisciplinary skills and perspectives
• UCD design teams


  • They are multidisciplinary as only by incorporating into the development process the concerns and expertise of the user and production teams that manufacture, distribute, maintain and market the product could a good design emerge
• The five stages of UCD


  1. Research

  2. Concept

  3. Design

  4. Implementation

  5. Launch
• Inclusive design


  Designing universally accessible products for all users including those with physical, sensory, perceptual and other challenges and impairments
• Products and services address the needs of the widest possible audience, irrespective of age or ability
• The effects of rapidly ageing populations, and growing numbers of people with disabilities, are having a profound effect on new product and service development
• Usability


  How easy it is to use a product or system
• Usability objectives


  • Ease of use
  • Efficiency of use
  • Unambiguous feedback
  • Clarity of human interface
• Usability objectives


  • Usefulness
  • Effectiveness
  • Learnability
  • Attitude (likeability)
• Usefulness


  The product enables user to achieve their goals - the tasks that it was designed to carry out and/or wants needs of user. Once users have learned the design, how quickly can they perform tasks?
• Effectiveness


  Quantitatively measured by speed of performance or error rate and is tied to a percentage of users. Use the design completely and accurately. Prevents errors and user can recover if errors occur.
• Learnability


  The user's ability to operate the system to some defined level of competence after some predetermined period of training. Also, refers to ability for infrequent users to relearn the system.
• Attitude


  The user's perceptions, feelings and opinions of the product, usually captured through both written and oral communication. Satisfaction or likability when the client uses or interacts with the product, service or system design.
• Benefits of enhanced usability


  • Product acceptance
  • User experience
  • Productivity
  • User error
  • Training and support
• Product acceptance


  The knowledge that a product or service paid for will meet up to its defined specifications
• User experience


  A person's perceptions and responses that result from the use or anticipated use of a product, system or service, this can modify over time due to changing usage circumstances
• Productivity


  Developing products and services with the user in mind can reduce time wasting or difficult to understand features
• Written and oral communication


  Satisfaction or likability when the client uses or interacts with the product, service or system design
• Good user-interface design


  • Low user error rate
  • High levels of user satisfaction
  • Easy to learn-simple uncomplicated, uncluttered interfaces
  • Easy to use-intuitive design, controls appear where anticipated and actions perform as expected
  • Easy to remember functions and operations are performed over time with an ease of repeatability and high level of competence retention
• Examples of good user-product interfaces

  • Simplicity and ease of use
  • Intuitive logic, organization and low memory burden
  • Visibility
  • Feedback
  • Affordance
  • Mapping
  • Constraints
• Population stereotypes


  Widespread responses and cultural expectations found in a user population about how equipment and products operate
• It is important to consider the intended User Population for any product (or system) you are designing
• Expectations that are found to be widespread in a population are known as conventions or stereotypes
• Making use of population stereotypes in the design


  Might sometimes be irrelevant
• For many controls, certain actions we do such as turning, sliding etc


  Will produce the expected result
• Many users can operate a product without having to learn how to operate it
• User population


  A range of users for a particular product or system
• Users can be classified by


  • Age
  • Gender
  • Physical condition
• Personae


  A profile of the primary target audience for a product