hci chap 4

• Interacting with technology is cognitive
• We need to take into account cognitive processes involved and cognitive limitations of users
• We can provide knowledge about what users can and cannot be expected to do
• We can identify and explain the nature and causes of problems users encounter
• We can supply theories, modelling tools, guidance and methods that can lead to the design of better interactive products
• Cognition


  What goes on in our heads when we carry out our everyday activities
• Cognitive processes


  • Thinking
  • Remembering
  • Learning
  • Daydreaming
  • Decision making
  • Seeing
  • Reading
  • Writing
  • Talking
• Cognition is distinct from emotional and volitional processes involved in wanting and intending
• Core cognitive aspects


  • Attention
  • Perception and recognition
  • Memory
  • Learning
  • Reading, speaking and listening
  • Problem-solving, planning, reasoning and decision-making
• Attention


  The process of selecting things to concentrate on at a point in time from the mass of stimuli around us
• Attention allows us to focus on information that is relevant to what we are doing
• Attention involves audio and/or visual senses
• Attention is easy or difficult depending on

  • Whether we have clear goals
  • Whether the information we need is salient in the environment
• Focussed and divided attention enables us to be selective in terms of the mass of competing stimuli but limits our ability to keep track of all events
• Information at the interface should be structured to capture users' attention, e.g. use perceptual boundaries (windows), colour, reverse video, sound and flashing lights
• Perception refers to how information is acquired from the environment via the different sense organs – eyes, ears, fingers – and transformed into experiences of objects, events, sounds, and tastes
• Text should be legible and icons should be easy to distinguish and read
• Representations of information need to be designed to be perceptible and recognizable across different media
• Design icons and other graphical representations so that users can readily distinguish between them
• Obvious separators and white space are effective visual methods for grouping information that make it easier to perceive and locate items
• Design audio sounds to be readily distinguishable from one another so that users can perceive how they differ and remember what each one represents
• Research proper colour contrast techniques when designing an interface, especially when choosing a colour for text so that it stands out from the background
• Haptic feedback should be used judiciously. The kinds of haptics used should be easily distinguishable
• Memory


  Involves recalling various kinds of knowledge that allow us to act appropriately
• We don't remember everything, memory involves filtering and processing what is attended to
• Context is important in affecting our memory (i.e., where, when)
• We recognize things much better than being able to recall things
• We are better at remembering images than words
• Interfaces are largely visual because of this
• Personal information management


  The design challenge of deciding the best way of helping users organize their content so that it can be easily searched
• Naming is the most common means of encoding files, but trying to remember a name of a file created some time back can be very difficult, especially when have 1000s and 1000s
• Memory involves 2 processes: recall-directed and recognition-based scanning
• File management systems should be designed to optimize both kinds of memory processes, e.g. Search box and history list
• Help users encode files in richer ways, provide them with ways of saving files using colour, flagging, image, flexible text, time stamping, etc
• Multifactor authentication (MFA)


  How to manage security concerns, especially preventing fraudulent transactions
• Reduce cognitive load by avoiding long and complicated procedures for carrying out tasks
• Design interfaces that promote recognition rather than recall by using familiar interaction patterns, menus, icons, and consistently placed objects
• Provide users with a variety of ways of labelling digital information (for example files, emails, and images) to help them easily identify it again using folders, categories, colour, tagging, time stamping, and icons
• Learning


  Closely connected with memory, involves the accumulation of skills and knowledge that would be impossible to achieve without memory
• Types of learning


  • Incidental - occurs without any intention to learn
  • Intentional - is goal-directed with the goal of being able to remember it