1. Human Factors Issues Chapter 8

3. What is Human Factors? Application of the scientific knowledge of human capabilities and limitations to the design of systems and equipment to produce products with the most efficient, safe, effective, and reliable operation

4. Human Factors Interface points Environment Skill level of user Interaction between: Human element Hardware element Software element Refrigerator Example

5. Human Element Memory Long term Short term Thinking and reasoning Visual perception Dialogue construction Individual skill level Individual sophistication

6. Hardware Element Size limitations Location of controls Compatibility with other equipment Potential need for portability Possible user training Display area Control knobs/switches

7. Software Element Simple, reliable data entry Menu driven Displays must not be overcrowded Dialogue must be jargon-free Feedback to users

8. Human Factors Process Analytic process that focuses on device objectives Design and development process that converts results of analyses into detailed equipment features Test and evaluation process which verifies that development process satisfies constraints

9. Steps in Human Factors Process Planning Analysis Conduct user studies Observations Interviews Focus groups Task analysis Benchmark usability tests User profile Setup advisory panel Crucial Pieces of Human Factors Process

10. Safety Should reflect system and personnel safety factors Failures Fail safe Failure indications Standards- ANSI, AAMI, ISO

11. Documentation Written to meet needs of various target populations Study capability and information needs of documentation users Mental abilities Physical abilities Previous experience Understanding of general operation Special needs of environment Attempt to avoid this!

12. Anthropometry Science of measuring human body and its parts and functional capacities Range of values: 5 th percentile female to 95 th percentile male Functional dimensions Psychological elements Workstation design considerations

14. Labeling Labels should be clear and direct Controls, displays, and other equipment that must be located should be clearly marked Receptacles and connectors should be marked with intended function or connection Hazard warnings should be prominent

15. Labeling?

16. Software Every user input should consistently produce some perceptible response from the computer Log-on should be automatically completed before any operation Allow for orderly shutdown in case of failure

17. Data Entry Consistent data entry transactions Minimize user input actions Feedback to user about acceptance or rejection of an entry Ability to change entry after it has been added

18. Feedback Present status, information, confirmation, and verification throughout the interaction Standby should be accompanied by ‘WAIT’ message Feedback should be self-explanatory

19. Prompts Commands, error messages, system capabilities, and procedures should be explained with prompts or help instructions Missing data/aborting changes should be prompted Factual and informative dialogue Displayed in standardized area

20. Defaults Currently defined default values should be provides and automatically displayed User should be prompted for acceptance of defaults Users should be able to set their own default