1. the human


From what you have learned about cognitive psychology, devise appropriate guidelines for use by interface designers. You may find it helpful to group these under key headings: for example, visual perception, memory, problem solving, etc, although some may overlap such groupings.


Guidelines are just what they say they are: guidelines. They provide for a consistent look and feel for an interface, as well as trying to exclude the more obvious mistakes that can be made from a psychological perspective. However, there are occasions when such constraints should be broken; for new interaction devices, for example, or to create a unique style of product.

Because of this, there is no one correct answer to this question: some will be more cognitively friendly than others, that is all. Guidelines can range from the general principle type shown below down to highly detailed information on what each component in a display should look and behave like.

Some examples of guidelines with cognitively solid foundations are shown below - this is not an exhaustive set by any means

  • Colour: don't show details in blue. Remember certain users can confuse green and red. Remember the social expectations of colours (e.g., in Western culture, red - stop, danger, hot; blue - cold; green - go).
  • Text: don't use all capital letters in text. Use a serif font for large blocks of text. Dark characters on a light screen are read more accurately and preferred.
  • Functionality: limit the number of things to be remembered to 7, and preferably to 5. Group things according to function.
  • Problem solving: use analogy and metaphor to aid learning and performance.

This exercise should encourage students to look into the literature on human factors, cognitive psychology and human physiology, and come up with some hard evidence about human limitations. This can then be used to provide informed guidelines.

Other exercises in this chapter

ex.1.1 (ans), ex.1.2 (ans), ex.1.3 (ans), ex.1.4 (tut), ex.1.5 (tut), ex.1.6 (open), ex.1.7 (open)

all exercises for this chapter