1. Chapter 5 Attention and Memory Constraints Presentation By: Sybil Calvillo

2. Overview Focusing Attention –Techniques for guiding information –Multitasking and interruptions –Autoprocessing Memory Constraints –Meaningful interfaces

3. The structure of information should be easy to navigate and allow users to find information quickly and easily.  Don’t put too much (or too little) information on a screen.  Use meaningful grouping and ordering to present a large amount of information  Important information should always be the easiest to see.  Don’t show information that is not needed often or at all. Focusing Attention – Structuring Information

4. Distractions lead to forgotten or repeated tasks. In the real world people use cognitive aids. Cognitive aids are external representations that are intended to gain attention at the time relevant to the task needed to be done. Systems should be designed to provide back up incase distractions lead to mistakes. - auto saving - reminder prompts Focusing Attention – Multitasking and Interruptions

5. Automatic Cognitive Process – processes that can be done quickly and need little attention. Ex. Short cuts, Ctrl+S for save Controlled Process – processes that are not automatic and require conscious thought. Ex.Calculus! Why are these important to interfaces? System designers should utilize automatic processes to design important features like saving documents. Ctrl+S provides an easy way for users to save documents without really thinking about it. Automatic Cognitive and Controlled Processes

6. The Stroop Effect

7. ZYP QLEKF SUWRG XCIDB WOPR ZYP QLEKF XCIDB SUWRG WOPR

8. RED BLACK YELLOW BLUE RED GREEN YELLOW BLACK BLUE BLACK

9. Users remember what is easiest and most meaningful. Designing meaningful interfaces helps users interact with computers. - Command Names - Icons Memory Constraints

10. Command Names Unix - grep – pattern searching tool,”global regular expression and print - lint – analyze programs written in C and pick out fluff - pr – format a file for printing but does not print it Command names should be meaningful so that users can remember them and use them correctly.

11. Icons Factors that determine the meaningfulness of icons: Context – Is the meaning of the icon affected by its location? Function – Would an icon make this function easier or more difficult to use? Representational form  Resemblance icons (deer crossing)  Exemplar icons (restaurant)  Symbolic icons (recycling)  Arbitrary icons (bio hazard)

13. Most people find recognition much easier to do than recall. Designing user interfaces should capitalize on this phenomenon. Graphical and meaningful interfaces give the user an intuitive feel and allow them to do little thinking. Since everything cannot be graphical and meaningful is a relative term, interface designers must do the best they can to make other commands as simple and organized as possible so that users will recognize them later. Recognition vs. Recall

14. Key Points (as presented in the book) Attention can be focused or divided: the events that we attend to in the world are filtered so that we can make sense of the world. Cognitive processes can be controlled or automatic. Memory is limited: the more information is processed, the more likely it will be remembered. The more meaningful names and icons are, the more likely they will be remembered. Material is far more easily recognized than recalled. When we carry out our everyday tasks we combine knowledge in the head with knowledge in the world. The use of graphical interfaces substantially reduces the amount of knowledge people have to remember about an interface. Memory of events and occurrences that are experienced is called episodic; memory of facts and general knowledge is called semantic.