2. Working Memory
– Short term
– Long term
Examples of working memory:
“1915 railroad switchman at station in Scotland forgot he
move train to active track”
“using a GPS map North side up while driving South
through a city—mental rotation of map necessary to
rectify visual map outside vehicle” (Wickens ,Liu,
&Becker).
The aviation industry has countless examples of human factor
errors that have been a contributing factor to accidents.
3.
4. Limits of Working Memory
• Capacity
• Confusability
• Time
• Attention and Similarity
• 7 + 2 chunks of information
• Working memory space utilizes “chunking” of data to minimize the space
occupied.
– Chunking bind a piece of data with another piece of data so that only one space is used in the
working memory.
Examples FOOT versus the number 1262
– Binding of chunks occur “occur when links or associations of past experience allows a person to lace
chunks in long term memory” ( Wickens , Liu, &Becker) 2004.
6. Current Application
• How can we assist our co-workers for memory retention during our fast past jobs
during our third shift work?
• Can you think of any time large groups of numbers become difficult or easy to
confuse? Have you ever missed a number during….
– Jagging in containers
• Flagging
• Hu numbers (nine digits)
– Hu791654235 poor retention for data entry
– Hu 791 654 235 good retention for data entry
7. Confusability and Similarity
• Certain letters may be more confusing visually, therefore creating difficulty in
recall.
– EGBDVC is more difficult to retrieve from working memory.
– WNWRUJ is easier to retrieve from memory (Wickens, Liu, & Becker) 2004.
– Adding to difficulty is repeating or responding back the numbers in order.
Attention
Working memory is aided when
• there are not excessive 0
• instructions take into consider memory in sequencing
• meaningful associations are used to link items in long term
memory
8. Cognitive and Physical Chunking
• Reduces numbers in working memory
• Aids in long term memory and easy retention by linking and binding chunks
• Shortened working memory transferred to long term memory after rehearsal
takes place
• Time
• In order for working memory to retain information, review of data, or
maintenance rehearsal must occur.
• Example. First digits for phone number may not be remembered by the
time done with last digit. Ten digit phone numbers are poor for memory
retention.
9. FORGETTING
• Memory declines within the first few days
• “Even when material is rehearsed to avoid forgetting, if there are many
association that must be acquired in a short period of time; they can interfere with
each other or become confused , particularly if the associations pertain to similar
material. New associations interfere with older associations “(Wickens, Liu, &
Becker) 2004.
• PROSPECTIVE MEMORY: forgetting to do something in the future. This has
occurred with air traffic controllers and aircraft collisions have resulted. Examples
are forgetting to continue with the movement of aircraft from one point on the
airfield to another. (future NEX Gen implimen.ation –GPS tracking on the ground
and in air of proximity of aircraft viewable by each aircraft, may alleviate some of
these issues by 2020).
10. Summary
• Supervisors and leads must be aware of the limits of working memory in direct
correlation to the capabilities of their employees.
• Keeping in mind the limits when dealing with employees may lead to the retention
of employee base and improvements in initial on the job training.
• OTHER ISSUES THAT AFFECT EMPLOYEE RETENTION AND BUSINESS SUCCESS TO BE
DISCUSSED AND VIEWED.
– Situational Awareness
– Factors affecting Decision Making Performance
– Personnel Selection
– Work Load and Stress
– Factors that Cause or Contribute to Accidents
– Decision Making Models
These subjects can all be found within the book Human Factors Engineering.
11. References
• Garland, d. J., Wise, J. A., & Hopkin , V.D. (1999). Handbook of Aviation Human
Factors. Mahwah, New Jersey: Lawrence Erlbaum Associates
• Wickens , D.C., Liu, J.D., & Becker, S.E. (2004). An Introduction to Human Factors
Engineering. Upper Saddle River, New Jersey: Pearson Education
• http://www.Wikipedia.images
• http://www.play.google.com
