User Psychology

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User Psychology
ITKP103 Human Being and Information
System http//www.cs.jyu.fi/ky/kurssit/itkp103/ind
ex.html Sacha Helfenstein sh_at_cc.jyu.fi Lectures
28.10, 2.11., and 4.11.2005
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Perception

• Perception ? mental copy of stimuli
• Perception is the process and product of actively
  selecting and organizing sensory information.
• Limits and Laws (e.g., contrasts, 3D, Faces,
  Gestalt Laws

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Limits of Perception Light

• Light impression Wavelength of ca. 380 nm to 740
  nm
• Color spectrum Differentiation of ca. 10 mio
  colors

red green blue redgreen greenblue redblue redgreenblue zero light
red green blue redgreen greenblue redblue redgreenblue zero light
red green blue redgreen greenblue redblue redgreenblue zero light
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Wavelenght Sensitivity of Cones
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The Opponent Process Theory

• Cells are connected so as to place sensations of
• red in opposition to green
• blue in opposition to yellow
• black in opposition to white

(Hering, 1878 Hurvich Jamison, 1957)
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Psychophysics of Sensation

• Weber (1846) Just noticable difference (JND,
  ?I) kI (stimuli-specific)
• Fechner (1860) Sensation (S) K log I

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Limits of Perception Sound

• Sound impression Frequencies between ca. 10Hz
  and 20kHz, with frequencies around 3500Hz
  appearing the loudest
• Volume Sound pressures from 0dB - 85bB (damaging
  level) 130dB (pain level) - ?

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Gestalt Laws
In search of the Good Figure The whole is
different from the sum of the stimuli

• Proximity
• Closure Figure-Ground
• Similarity
• Common Fate Continuity
• Symmetry

e.g., Koffka (1935)
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Application
Proximity
Similarity
Continuity
Closure
e.g., Music
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Perception and Attention

• Factors influencing visual representation, e.g.,
• Visual saliency (e.g., pop-out, contrasts,
  familiar schemata)
• Cognitive saliency (e.g., gist, consistency,
  context)
• Principles of perception (e.g., Gestalt laws)
• Task goal
• Key properties of attention
• Division and Selection
• Control vs. Automation

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Stroop Effect (1935)
Hattu Kortti Ranska Kone Kenkä Veitsi
Punainen Violetti Oranssi Vihreä Valkoinen Sininen
Punainen Violetti Oranssi Vihreä Valkoinen
Sininen Violetti Keltainen Musta Vihreä Sininen
Oranssi Valkoinen
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Important psychological concepts

• Capacity
• limitations of information processing
• Selectivity
• focus of information processing
• Division
• parallel processing
• Construction
• organization of information...
• ... into meaningful wholes

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Users Learning and Thinking

• Repetitio mater studiorum est
• Consistency and Interference
• Recognition is easier than recall
• Learning and thinking is context dependent
• Law of Experience -gt Transfer of Learning
• Familiarity
• Affordance
• Metaphors (metapherein to transfer)