Chapter 5 Memory. Human Performance Engineering Robert W. Bailey, Ph.D. Third Edition. Designers should be aware of three types of human memory: sensory, short-term, long-term 1. Sensory – Persistence of a stimulus.
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Human Performance Engineering
Robert W. Bailey, Ph.D.
Designers should be aware of three
types of human memory:
sensory, short-term, long-term
1. Sensory – Persistence of a stimulus
For vision- Duration of sensory memory can be lengthened by optimizing the stimulus- background contrast.
Difficulties with visual sensory memory
would show up as errors characterized
by a lack of pattern or an excess of visual confusion.
More errors in the rightmost positions
and fewer in the left positions.
More errors in the center positions
than in the end positions.
2. Short Term Memory – Working memory, place to hold information temporarily.
External sources- By way of the perceptual process.
Internal sources- The result of reasoning, decision making, and problem solving.
Information is encoded into a form
that can be conveniently stored
in human memory.
Some visual information is transferred
into auditory form.
Can hold about 6 units of information (Chunks)
People forget longer messages sooner-
The shorter the code the better.
Try to limit interference.
Retains information in short-term memory.
Other activities should not interfere with the rehearsal process.
Divide longer strings of characters
into groups of three or four
to help rehearsal.
217 964 831
427947247 - > 427 947 247
24657435-> 24 65 74 35
NTH EDO GSA WTH ECA TRU
“The dog saw the cat run”
Errors will tend to occur in certain character positions more than others.
Ex. In a seven-character code
most errors tend to occur in the
fifth position and the fewest usually
occur in the first position.
Auditory Stimuli – Last character tends to be recalled as well as the first character.
Visual Stimuli – Last character tends to be mistaken more often.
Don’t require users to retain
even a small amount of information
for over 20 seconds,
if rehearsal is not possible.
Primarily, we lose material from
short-term memory by replacing it
with new information.
New information seems to push out old
Limited capacity – six or fewer units.
Relatively short duration – less than 20 seconds.
Page 151- Peg Words
3. Long - term memory – Permanent memory storage. Relies heavily on organization. Learning, remembering, forgetting
forgotten information – lost access to it.
Belief –People do not lose information permanently. Hypnosis
Three operations take place related to remembering and forgetting:
Encoding, storage, and retrieval.
Process of deciding how to classify information. Sometimes only the essence of what was sensed will be encoded.
Ex. Good movie, lousy dinner, nice guy
Storage – Putting information into long-term memory.
Search in different locations when
trying to remember something.
Try to recall how the information was
May be due to a failure of any of these three operations.
E.G. original coding may be incorrect,
info may be degraded during storage,
info may be difficult to retrieve
because searching is done in wrong place.
Proactive interference – material learned prior to the learning of new material may interfere with the use of the new material in a performance situation.
Exp. Learn Task A, Learn Task B, Perform B.
Y=MX+B, Y=A+BX Y=A+BX
Designers must find out what kind of responses have already been learned and then incorporate as much as possible the same kind of responses in the new system.
Retroactive interference –
Exp. Learn task A, Learn task B, Perform A
Lotus 1-2-3, Excel, Lotus 1-2-3
Two commonly used ways of measuring remembered information.
Recalling info is much more difficult than recognizing info.
Designer should make full use of this fact.
MNEMONICS – Conscious ways for helping to ensure the retention of material that would otherwise be forgotten.
Ex. String around your finger, complex visual imagery schemes
Cognitive performance aids- Require a person to either reduce or elaborate on information being received.
Frequently take the from of acronyms:
Homes- Great Lakes
Roygbiv- Colors of spectrum
Ex. 9 times table, string around your finger
Disadvantage – Reduce the information so much
that it is no longer possible to reconstruct the original.
Adding information to make the material easier to remember.
By taking greater advantage of meaning that already exists in words, phrases, or concepts.
Every good boy does fine – lines of the Treble Clef.
Information that is coded along several dimensions is less likely to be forgotten.
A mental picture is created and viewed.
Man named S. memorized 50 numbers in 3 minutes.
Imagined a familiar street and he would place objects along the way.