Chapter 3: Cognitive Aspects

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The main aims of this chapter are to:

  • Explain what cognition is and why it is important for interaction design.
  • Discuss what attention is and its effects on our ability to multitask.
  • Describe how memory can be enhanced through technology aids.
  • Explain what mental models are.
  • Show the difference between classic internal cognitive frameworks (e.g. mental models) and more recent external cognitive approaches (e.g. distributed cognition) that have been applied to HCI.
  • Enable you to try to elicit a mental model and be able to understand what it means.


Imagine it is late in the evening and you are sitting in front of your computer. You have an assignment to complete by tomorrow morning - a 3000 word essay on how natural are natural user interfaces - but you are not getting very far with it. You begin to panic and start biting your nails. You see the email icon on your smartphone light up indicating new email has arrived. You instantly abandon your textbook and cradle your smartphone to see who it is from. You're disappointed. Just another message about an upcoming conference you have no interest in. Before you know it you're back on Facebook to see if any of your friends have posted anything about the party you wanted to go to but had to say no. A Skype message flashes up and you see it is your dad calling. You answer it and he asks if you have been watching the football game. You say you are too busy working toward your deadline and he tells you your team has just scored. You chat with him and then say you have to get back to work. You realize 30 minutes has passed and you return your attention to the essay title. You type 'Natural User Interface' into Google Scholar and click on the top article. You click on the PDF icon for the article and it takes you to another page that requires a login and password. You don't have them for that publisher. You go back to Google Scholar and click on the next link. This time it takes you to the ACM digital library that your university has access to. But before you realize it you have clicked on the BBC Sports site to check the latest score for the football game. Your team has just scored again. Your phone starts buzzing. Two text messages this time! One is from your dad and another one from your girlfriend. You reply to both and within seconds they text back.

And on it goes. You glance at the time on your computer. It is 3.00 a.m. You really are in a panic now and finally switch everything off except your word processor.

As noted by Hafner (2004), a technology reporter, "distracting oneself used to consist of sharpening a half-dozen pencils or lighting a cigarette. Today, there is a universe of diversions to buy, hear, watch, and forward, which makes focusing on a task all the more challenging." In the past 10 to 15 years it has become increasingly common for people to be always switching their attention between multiple tasks. At its most extreme form, such behavior has been found to be highly addictive: instead of focusing on our work we're really waiting for the next hit - be it a new email, text, Facebook posting, news feed, and so forth. For some, such chronic media multitasking can be debilitating as they are unable to focus their attention on a single task for very long. For others, they have become very adept at using multiple sources of information to perform multiple tasks. The study of human cognition can help us understand these and other new kinds of computer- augmented behaviors by examining humans' abilities and limitations when interacting with technologies.

In this chapter we examine cognitive aspects of interaction design. Specifically, we consider what humans are good and bad at and show how this knowledge can be used to inform the design of technologies that both extend human capabilities and compensate for their weaknesses. We also look at some of the influential cognitive-based conceptual frameworks that have been developed for explaining the way humans interact with computers. (Other ways of conceptualizing human behavior that focus on the social and emotional aspects of interaction are presented in the following two chapters.)