UGS 302 – Usability and
UCD
- Scientific Underpinnings
- Memory and Cognition
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Day 5
R. G. Bias | School of Information | UTA 5.424 | Phone: 512 471 7046 | rbias@ischool.utexas.edu
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Objectives
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After this class you will be able to (it is my
hope!):
• Explain the human memory system
• Explain how psychologists gathered data to infer the
two-stage theory of memory
• Explain some aspects of the psychology of reading
• Explain how perceptual and cognitive psychology
influence HCI designs
• Have an excellent memory for “VAM”
• Discuss the importance of designing systems to match
the human.
R. G. Bias | School of Information | UTA 5.424 | Phone: 512 471 7046 | rbias@ischool.utexas.edu
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Whole point . . .
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• Let’s design systems to fit people
instead of the other way around.
R. G. Bias | School of Information | UTA 5.424 | Phone: 512 471 7046 | rbias@ischool.utexas.edu
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Human Information Processing
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• How do human beings take in and process
information?
– Sensory psychology – how humans transform physical
energy (e.g., light and sound waves) into sensory signals to
and in the brain.
– Perceptual psychology – how humans interpret these
sensory signals as perceptions.
– Cognitive psychology – how humans think about these
perceptions, and previous experiences, and their own mental
creations, and . . .
– Psycholinguistics – The psychology of language -- what
goes on between the time I have a thought and you have the
same (or similar!) thought, whether I say it or write it.
R. G. Bias | School of Information | UTA 5.424 | Phone: 512 471 7046 | rbias@ischool.utexas.edu
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What do we know about
humans?
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– In the physical realm: Anthropometry.
– These days we’re more interested in the
cognitive realm.
– Question: Can you remember a 30-digit
number?
– I say that you can, right now, without practice,
seeing it only once, for 1 second, with no time to
rehearse.
R. G. Bias | School of Information | UTA 5.424 | Phone: 512 471 7046 | rbias@ischool.utexas.edu
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i
3333333333333333333333333333333
R. G. Bias | School of Information | UTA 5.424 | Phone: 512 471 7046 | rbias@ischool.utexas.edu
6
Experiment 1
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Instead of numbers, I’ll present CVC
(consonant-vowel-consonant) strings -- like
“NEH”.
10 CVCs, one at a time.
Presented visually.
Don’t have to remember them in order.
Pencils down.
Ready?
R. G. Bias | School of Information | UTA 5.424 | Phone: 512 471 7046 | rbias@ischool.utexas.edu
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BOV
NAZ
TOL
RIJ
DIH
REN
WUK
CAQ
GOC
MEB
R. G. Bias | School of Information | UTA 5.424 | Phone: 512 471 7046 | rbias@ischool.utexas.edu
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BOV
NAZ
TOL
RIJ
DIH
REN
WUK
CAQ
GOC
MEB
R. G. Bias | School of Information | UTA 5.424 | Phone: 512 471 7046 | rbias@ischool.utexas.edu
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Experiment 2
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•Now, 10 new CVCs.
•Same task -- recall them.
•This time, after we read the 10th item,
we’ll all count backwards from 100 by 3s,
aloud, together.
•Then when I say “Go,” write down as
many of the 10 CVCs as you can.
•Pencils down.
•Ready?
R. G. Bias | School of Information | UTA 5.424 | Phone: 512 471 7046 | rbias@ischool.utexas.edu
10
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VAM
LUN
XOP
REH
WIV
CIT
JEG
KUC
ZOB
YAD
R. G. Bias | School of Information | UTA 5.424 | Phone: 512 471 7046 | rbias@ischool.utexas.edu
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VAM
LUN
XOP
REH
WIV
CIT
JEG
KUC
ZOB
YAD
R. G. Bias | School of Information | UTA 5.424 | Phone: 512 471 7046 | rbias@ischool.utexas.edu
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Experiment 3
•
•
•
•
•
•
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Same as Experiment 2.
Yet 10 more CVCs.
Backwards counting.
Don’t have to recall them in order.
Pencils down.
Ready?
R. G. Bias | School of Information | UTA 5.424 | Phone: 512 471 7046 | rbias@ischool.utexas.edu
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GEP
TIV
WOH
LUP
MAZ
SEX
KOL
RUC
NID
BIR
R. G. Bias | School of Information | UTA 5.424 | Phone: 512 471 7046 | rbias@ischool.utexas.edu
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GEP
TIV
WOH
LUP
MAZ
SEX
KOL
RUC
NID
BIR
R. G. Bias | School of Information | UTA 5.424 | Phone: 512 471 7046 | rbias@ischool.utexas.edu
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So?
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• So, the answer to “Can you remember a 30digit number?”, is . . . It depends. On what?
– Whether you hear or see the number.
– Whether the number is masked.
– Whether you have time to rehearse.
– Whether you can “chunk” the numbers.
– If there are any intervening tasks.
– How meaningful the number is.
– WHAT the number is.
So, what’s a usable interface?
It depends.
R. G. Bias | School of Information | UTA 5.424 | Phone: 512 471 7046 | rbias@ischool.utexas.edu
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Psycholinguistics
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• The psychology of language.
• What goes on from the time I get an idea
until you have the same idea,
– Whether I speak my idea (speech
production, auditory science, speech
perception)
– Or write my idea (motor movements, visual
system, reading)
R. G. Bias | School of Information | UTA 5.424 | Phone: 512 471 7046 | rbias@ischool.utexas.edu
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The Psychology of Reading
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• Except for fairly rare cases of “phonetic
symbolism” (onomatopoeia) words have
no inherent meaning.
– (And rarer cases of “orthographic
symbolism”!!)
• So, READING is the interpreting of
words, the acts that go on to impose
meaning, from within, on external visual
stimuli.
R. G. Bias | School of Information | UTA 5.424 | Phone: 512 471 7046 | rbias@ischool.utexas.edu
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Some facts about reading
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• Eyes of the mature reader move rhythmically across the page
(from left to right).
• Eye movement consists of fixations, saccades, regressions, and
return sweeps.
• No information is taken in during saccades (10-25 msec),
regressions (same duration), or return sweeps (40 msec).
• During fixation (250 msec) a visual pattern is reflected onto the
retina.
• Span of perception = amount of print seen during a single fixation.
• Span of perception = 12 letter spaces for good readers, 6 for poor
readers.
R. G. Bias | School of Information | UTA 5.424 | Phone: 512 471 7046 | rbias@ischool.utexas.edu
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More facts
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• Span of recognition – 1.21 words for senior high, 1.33 words for
college readers.
• So, 7 to 8 fixations per line of print.
• As content gets tougher, duration of fixations, not number,
changes (increases).
• Regressive movements aren’t systematic. Used when attention
is faltering.
• College readers have 1 regressive movement per 3 or 4 lines of
print. Immature readers have 3 or 4 regressions per line.
R. G. Bias | School of Information | UTA 5.424 | Phone: 512 471 7046 | rbias@ischool.utexas.edu
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Iconic Memory
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• Earlier I mentioned a two-stage memory process – STM and
LTM.
• A third stage, Iconic Memory: The unidentified, “pre-categorical”
pattern of lines, curves and angles; formed in about 100 msec.
• Icon can hold up to 20 letter spaces.
• Pattern recognition routines are applied to the lines, curves.
• It takes about 10 – 20 msec to read each letter out of the iconic
memory.
• Neural signal takes about 30 msec to go from the retina to the
visual cortex.
R. G. Bias | School of Information | UTA 5.424 | Phone: 512 471 7046 | rbias@ischool.utexas.edu
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Iconic Memory (cont’d.)
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• At some point, thanks to pattern recognition routines, letters are
read out.
• Letters are transformed into abstract phonemic representations.
• The abstract phonemes are used to search the mental lexicon.
• About 300 msec after the eye has fallen upon the page, the first
word is “understood,” i.e., placed in Primary Memory (STM,
Working Memory).
• Syntactic and semantic rules are applied to gain the meaning of
the sentence.
R. G. Bias | School of Information | UTA 5.424 | Phone: 512 471 7046 | rbias@ischool.utexas.edu
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How do you know, Randolph?
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• Psycholinguists employ a variety of methods to
acquire this data about human behavior.
• One question: Why do we think readers routinely
transform the visual representation into a phonological
representation?
– Cognitive economy – all (healthy) new readers
come to the task as skilled hearers.
– “I thought you said something about data?”
R. G. Bias | School of Information | UTA 5.424 | Phone: 512 471 7046 | rbias@ischool.utexas.edu
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Rubenstein et al. (1971)
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• Used a lexical decision task (word/nonword?).
• Two types of nonwords – homophonous (with real
words), like burd and nonhomophonous like rolt.
Equally “wordlike.”
• Longer latencies for burd.
• Similarly, longer for real homophones like meat.
• Pointed to “false matches” in the mental lexicon.
R. G. Bias | School of Information | UTA 5.424 | Phone: 512 471 7046 | rbias@ischool.utexas.edu
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More Data
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• McCusker et al. (1977) proofreading experiment
– Homophonous typos (e.g., furst) went undetected
more often than nonhomophonous typos (e.g.,
farst).
• Gough and Cosky (1977) used the Stroop task.
– Nonwords homophonous with color words (e.g,. bloo) led to
more interference than control words (e.g., blot) or nonwords
nonhomophonous with color words (e.g., blop).
• I found readers took longer to process words with
irregular “spelling-to-sound rules” (e.g., pint) than
words with regular rules (e.g., hint) (Bias, 1978).
R. G. Bias | School of Information | UTA 5.424 | Phone: 512 471 7046 | rbias@ischool.utexas.edu
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The Point
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• The reasons for this somewhat esoteric
discourse on the psychology of reading
are:
– To communicate the complexity that is
human information processing
– The illustrate the ways scientists go about
answering questions about info processing
– To sensitize you to the sorts of things
known about human behavior
R. G. Bias | School of Information | UTA 5.424 | Phone: 512 471 7046 | rbias@ischool.utexas.edu
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Upcoming
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• This Thursday – more presentations.
• Also, remember:
– Bring to class a URL showing a good and
poor WEB design. (Actually, send me the
URLs in advance of class – say, by
1/29/2013, midnight tonight, and I’ll have it
ready to go.)
R. G. Bias | School of Information | UTA 5.424 | Phone: 512 471 7046 | rbias@ischool.utexas.edu
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