1. Attention & Human Decision Making  Decision Making is the end goal of Human Information Processing.  However, people are not optimal decision makers, due to inattention, personal biases,  and errors in judgment.

2. Types of Human Attention  Selective Attention  Focused Attention  Divided Attention  Sustained Attention

3. Selective Attention  Selective Attention Requires monitoring of several channels of information to perform a single task.  Examples: Pilot Nuclear power operator Receptionist

4. Selective Attention Stressors Load Stress - Too much information at once Examples: Two simultaneous talkers Improperly trained workers Speed Stress - Information presented too quickly Examples: Dials changing too quickly to comprehend ATC instructions transmitted too rapidly

5. Selective Attention Guidelines  Decrease number of channels, may increase signal rate.  Decrease stresses, allow more channels to be monitored.  Place channels closer together.  Train workers to be effective workers.

6. Focused Attention  A person must attend to one source of information and ignore all other sources. Examples: Conversations in noisy environment Distracting audience side conversations 

7. Focused Attention Guidelines  Make channels distinct  Separate channels  Reduce competing channels  Make channel of interest more distinct

8. Divided Attention  Limited capacity to process information.  Required to do more than one task at a time, also called “time sharing”.  Two theories regarding information processing Single-Resource Theory Multiple-Resource Theory

9. Divided Attention Guidelines  Where possible, the number of potential sources of information should be minimized.  Where time-sharing is likely to stress a person’s capacity, the person should be provided with information about the relative priorities of the tasks so that an optimum strategy of dividing attention can be formulated.  Efforts should be made to keep the difficulty level of the tasks as low as possible.

10. Guidelines - continued  The tasks should be made as dissimilar as possible in terms of demands on processing stages, input and output modalities, and memory codes.  Especially when manual tasks are time-shared with sensory or memory tasks, the greater the learning of the manual task, the less will be its effect on the sensory or memory tasks.

11. Sustained Attention  Vigilance - Concerns the ability of observers to maintain attention and remain alert to stimuli over prolonged periods of time.

12. Sustained Attention Guidelines  Provide appropriate work-rest schedules.  Provide task variation.  Increase the conspicuity of the signal.  Reduce uncertainty as to when and where the signal will occur.  Inject artificial signals and provide operators with feedback on their performance.

13. Guidelines - continued Provide adequate training of observers to make clear the nature of the signals to be identified. Improve motivation by emphasizing the importance of the task being performed. Reduce the rate at which stimuli (which may or may not be signals) are presented. Maintain noise, temperature, illumination, and other environmental factors at optimal levels.

14. Aging Effects & Information Processing  Effects of Age usually do not become noticeable until after the age of 65 or so.  Decrease rate of performance.  Increased disruption of working memory due to shift of attention.

15. Aging Effects - continued  Difficulty in searching and retrieving material from long-term memory.  Difficulty in dealing with incompatibility.  Decrements in perceptual encoding of ambiguous stimuli.

16. Elderly Design Guidelines Designing Information Processing Task for Elderly Strengthen amplitude displayed signals. Design controls/displays to reduce irrelevant details. Maintain a high level of conceptual, spatial,  and movement compatibility.

17. Elderly Guidelines - continued Reduce time-sharing demands. Provide time between the execution of a response and the signal for the next response. Allow more time and practice to learn the material.