Range Effects in Experiments on People E' C' Poulton

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Range Effects in Experiments on People E. C.
Poulton
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• Range Effect
• Bias in response
• Tied to within-subjects design
• Transfer of training effect
• Sensory magnitude
• Central Tendency
• Stimulus generalization, absolute judgments,
  serial effects

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• Latin Square design
• ABBA
• Asymmetrical Transfer
• Range effect produces unreliable results.

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• A Typical Range Effect
• Results dependent on range

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• Another Transfer of Training Effect
• Alphanumeric Matrices, a range effect with a bias
  in a single direction.

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• Another Example of Transfer of Training Effect
• Short term memory scanning
• Serial Learning effect a tendency to remember
  the first and last items on a list best and the
  middle items the least.

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• Another Transfer of Training Effect
• Combined Stress
• The motivation to maintain an average level of
  performance

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• Ratings of Sensory magnitude
• Subjectively determining acceptable levels of
  car noise. Ratings gravitated to the center

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• Direct Magnitude Estimates
• Stevens Power Law S kIa
• S sensation magnitude
• k constant
• I stimulus intensity
• a power exponent

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• Central Tendency
• Triangle with no apparent aesthetic value
• Bets that dont lose money
• Perhaps a lack of interest

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• Visual
• Shape constancy
• Ellipse study
• An ellipse closer to the middle is chosen.
• Size constancy
• Standards study
• Large standards were underestimated, small
  standards overestimated.

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• Step tracking
• A tendency to error toward the middle of the
  range.
• Changing the range changes the average error.

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• Stimulus Generalization, Absolute Judgments,
  Serial Learning
• Stimuli near the middle of the range are at a
  disadvantage.

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• Stimulus Generalization
• A green closer to the center of green was chosen
  over the original stimulus

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• Absolute judgments
• Middle categories again confused with each other

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• Stimulus and response probability
• Studying the connection between the probabilities
  and the responses
• Probability learning
• Maximizing probability, if well paid
• Otherwise, each source is picked roughly equal to
  frequency of the signals from that source.

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• Theories
• Many different theories to account for range
  effects.
• Central nervous synaptic gating mechanism
• Physiology of the sense organs
• Parallel processing
• Exhaustive serial scanning
• Adaptation level

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• Avoiding Range Effects
• within-subjects design
• Range of responses
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