HCI121 I What is Interaction Design?

• Interaction Design

  • Designing interactive products to support people in their everyday and working lives
  • The design of spaces for human communication and interaction
• Goals of Interaction Design

  • Develop usable products
  • Involve users in the design process
• Need to take into account in Designing

  • Who the users are
  • What activities are being carried out
  • Where the interaction is taking place
  • Need to optimize the interactions users have with a product – Such that they match the users activities and needs
• 50s - Interface at the hardware level for engineers - switch panels
• Human-computer interaction (HCI) is:

  “concerned with the design, evaluation and implementation of interactive computing systems for human use and with the study of major phenomena surrounding them” (ACM SIGCHI, 1992, p.6)
• Interaction design (ID) is:

  “the design of spaces for human communication and interaction” -Winograd (1997)

  • Increasingly, more application areas, more technologies, and more issues to consider when designing ‘interfaces’
• Academic disciplines contributing to ID:

  – Psychology

  – Social Sciences

  – Computing Sciences

  – Engineering

  – Ergonomics

  – Informatics
• Design practices contributing to ID:

  – Graphic design

  – Product design

  – Artist-design

  – Industrial design

  – Film industry
• Interdisciplinary fields that ‘do’ interaction design:

  – HCI

  – Human Factors

  – Cognitive Engineering

  – Cognitive Ergonomics

  – Computer Supported Co-operative Work

  – Information Systems
• interaction designers - people involved in the design of all the interactive aspects of a product
• usability engineers - people who focus on evaluating products, using usability methods and principles
• web designers - people who develop and create the visual design of websites, such as layouts
• information architects - people who come up with ideas of how to plan and structure interactive products
• user experience designers - people who do all the above but who may also carry out field studies to inform the design of products
• Core characteristics of interaction design

  • users should be involved through the development of the project

  • specific usability and user experience goals need to be identified, clearly documented and agreed at the beginning of the project

  • iteration is needed through the core activities
• Usability goals

  • Effective to use

  • Efficient to use

  • Safe to use

  • Have good utility

  • Easy to learn

  • Easy to remember how to use
• User experience goals

  – Satisfying

  - rewarding

  – Fun

  - support creativity

  – Enjoyable

  - emotionally fulfilling

  – Entertaining …and more

  – Helpful

  – Motivating

  – Aesthetically pleasing

  – Motivating
• Design principles

  • Generalizable abstractions for thinking about different aspects of design

  • The do’s and don’ts of interaction design

  • What to provide and what not to provide at the interface

  • Derived from a mix of theory-based knowledge, experience and common-sense
• Feedback

  • Sending information back to the user about what has been done

  • Includes sound, highlighting, animation and combinations of these – e.g. when screen button clicked on provides sound or red highlight feedback:
• Constraints

  • Restricting the possible actions that can be performed

  • Helps prevent user from selecting incorrect options

  • Three main types (Norman, 1999)

  – physical

  – cultural

  – logical
• Physical constraints

  • Refer to the way physical objects restrict the movement of things

  – E.g. only one way you can insert a key into a lock

  • How many ways can you insert a CD or DVD disk into a computer?

  • How physically constraining is this action?

  • How does it differ from the insertion of a floppy disk into a computer?
• Logical constraints

  • Exploits people’s everyday common sense reasoning about the way the world works
• Cultural constraints

  • Learned arbitrary conventions like red triangles for warning

  • Can be universal or culturally specific
• Mapping

  • Relationship between controls and their movements and the results in the world
• Consistency

  • Design interfaces to have similar operations and use

  similar elements for similar tasks

  • For example: – always use ctrl key plus first initial of the command for an operation – ctrl+C, ctrl+S, ctrl+O

  • Main benefit is consistent interfaces are easier to learn and use
• When consistency breaks down

  • What happens if there is more than one command starting with the same letter? – e.g. save, spelling, select, style

  • Have to find other initials or combinations of keys, thereby breaking the consistency rule – E.g. ctrl+S, ctrl+Sp, ctrl+shift+L

  • Increases learning burden on user, making them more prone to errors
• Internal consistency refers to designing operations to behave the same within an application

  – Difficult to achieve with complex interfaces
• External consistency refers to designing operations, interfaces, etc., to be the same across applications and devices

  – Very rarely the case, based on different designer’s preference
• Affordances: to give a clue

  • Refers to an attribute of an object that allows people to know how to use it

  – e.g. a mouse button invites pushing, a door handle affords pulling

  – Norman (1988) used the term to discuss the design of everyday objects

  • Since has been much popularised in interaction design to discuss how to design interface

  objects

  – e.g. scrollbars to afford moving up and down, icons to afford clicking on
• What does ‘affordance’ have to offer interaction design?

  • Interfaces are virtual and do not have affordances like physical objects

  • Norman argues it does not make sense to talk about interfaces in terms of ‘real’ affordances

  • Instead interfaces are better conceptualized as ‘perceived’ affordances

  – Learned conventions of arbitrary mappings between action and effect at the interface

  – Some mappings are better than others
• Usability principles

  • Similar to design principles, except more prescriptive

  • Used mainly as the basis for evaluating systems

  • Provide a framework for heuristic evaluation
• Usability principles (Nielsen 2001)

  • Visibility of system status

  • Match between system and the real world

  • User control and freedom

  • Consistency and standards

  • Help users recognize, diagnose and recover from errors

  • Error prevention

  • Recognition rather than recall

  • Flexibility and efficiency of use

  • Aesthetic and minimalist design

  • Help and documentation
• Usability means easy to learn, effective to use, and provide an enjoyable experience
• • 60-70s - interface at the programming level - COBOL, FORTRAN
• • 70-90s - Interface at the terminal level - command languages
• • 80s - Interface at the interaction dialogue level - GUIs, multimedia
• • 90s - Interface at the work setting - networked systems, groupware
• • 00s - Interface becomes pervasive – RF tags, Bluetooth technology, mobile devices, consumer electronics, interactive screens, embedded technology