Posts Tagged ‘affordance’

Knowledge at basic level

May 15, 2010

“Our knowledge at the basic level is mainly organized around part-whole divisions. The reason is that the way an object is divided into parts determines many things.

  1. First, parts are usually correlated with functions, and hence our knowledge about functions is usually associated with knowledge about parts.
  2. Second, parts determine shape, and hence the way that an object will be perceived and imaged.
  3. Third, we usually interact with things via their parts, and hence part-whole divisions play a major role in determining what motor programs we can use to interact with an object. Thus, a handle is not just long and thin, but it can be grasped by the human hand.”

Lakoff (1987) p.47

Gestalt (‘What is it?’) and affordance (‘What can I do with it?): core processes in screen communication

Isomorphic correspondence

June 6, 2008

Isomorphic correspondence is similar to what Norman calls affordances

“the relationship between the appearance of a visual form and a
comparable human behaviour.”

From: Wroblewski, Luke (2002), Site-Seeing: A Visual Approach to Web-Usability, New York: Hungry Minds, p.137

Don Norman’s design principles

June 5, 2008

Referring to Don Norman’s ‘Design of Everyday Things’

  1. Visibility – (…) The more visible functions are, the more likely users will be able to know what to do next. In contrast, when functions are “out of sight,” it makes them more difficult to find and know how to use. (…)
  2. Feedback – (…) Feedback is about sending back information about what action has been done and what has been accomplished, allowing the person to continue with the activity. Various kinds of feedback are available for interaction design-audio, tactile, verbal, and combinations of these. (…)
  3. Constraints – The design concept of constraining refers to determining ways of restricting the kind of user interaction that can take place at a given moment. There are various ways this can be achieved. (…)
  4. Mapping – This refers to the relationship between controls and their effects in the world. Nearly all artifacts need some kind of mapping between controls and effects, whether it is a flashlight, car, power plant, or cockpit. An example of a good mapping between control and effect is the up and down arrows used to represent the up and down movement of the cursor, respectively, on a computer keyboard. (…)
  5. Consistency – This refers to designing interfaces to have similar operations and use similar elements for achieving similar tasks. In particular, a consistent interface is one that follows rules, such as using the same operation to select all objects. For example, a consistent operation is using the same input action to highlight any graphical object at the interface, such as always clicking the left mouse button. Inconsistent interfaces, on the other hand, allow exceptions to a rule. (…)
  6. Affordance – is a term used to refer to an attribute of an object that allows people to know how to use it. For example, a mouse button invites pushing (in so doing acting clicking) by the way it is physically constrained in its plastic shell. At a very simple level, to afford means “to give a clue” (Norman, 1988). When the affordances of a physical object are perceptually obvious it is easy to know how to interact with it. (…)

From: Preece, J., Rogers, Y., Sharp, H. (2002), Interaction Design: Beyond Human-Computer Interaction, New York: Wiley, p.21

Don Norman’s design principles

June 5, 2008

Referring to Don Norman’s ‘Design of Everyday Things’

  1. Visibility – (…) The more visible functions are, the more likely users will be able to ow what to do next. In contrast, when functions are “out of sight,” it makes them more difficult to find and know how to use. (…)
  2. Feedback – (…) Feedback is about sending back information about what action has been done and what has been accomplished, allowing the person to continue with the activity. Various kinds of feedback are available for interaction design-audio, tactile, verLaI, and combinations of these. (…)
  3. Constraints – The design concept of constraining refers to determining ways of restricting the kind of user interaction that can take place at a given moment. There are various ways this can be achieved. (…)
  4. Mapping – This refers to the relationship between controls and their effects in the world. Nearly all artifacts need some kind of mapping between controls and effects, whether it is a flashlight, car, power plant, or cockpit. An example of a good mapping between control and effect is the up and down arrows used to represent the up and down movement of the cursor, respectively, on a computer keyboard. (…)
  5. Consistency – This refers to designing interfaces to have similar operations and use similar elements for achieving similar tasks. In particular, a consistent interface is one that follows rules, such as using the same operation to select all objects. For example, a consistent operation is using the same input action to highlight any graphical object at the interface, such as always clicking the left mouse button. Inconsistent interfaces, on the other hand, allow exceptions to a rule. (…)
  6. Affordance – is a term used to refer to an attribute of an object that allows people to know how to use it. For example, a mouse button invites pushing (in so doing acting clicking) by the way it is physically constrained in its plastic shell. At a very nple level, to afford means “to give a clue” (Norman, 1988). When the affordances of a physical object are perceptually obvious it is easy to know how to intert with it. (…)

From: Preece, J., Rogers, Y., Sharp, H. (2002), Interaction Design: Beyond Human-Computer Interaction, New York: Wiley, p.21