Toot Suite Survey
Do you drive? ___ YES ___ NO
Do you listen to music while driving? ___ YES ___ NO
Please provide brief singing sample: _______________
Do you ever sing while driving? ___YES ___ NO
How do questions make you feel? About self? experimenter?
How much did these feelings affect your answer?
TO OBSERVE IS TO CHANGE
Heisenberg Uncertainty Principle:
The more precisely one property is measured, the less precisely the other can be controlled, determined, or known.
In other words, the very act of trying to measure a thing introduces biases that distort the thing being measured.
In other words, we risk changing things by studying them!!!
The Totalitarian Experimenter
We want subjects to:
Be blank slatesLook, feel, think only as directedAccept instructions without questionRespond only to given info, no other info
Modes of Subject Defections
Willful or negligent undermining
Try to sabotage experiment
Try to figure out the experiment
Get bored
Get distracted
Over-cooperativeness
Self-presentation motives
Desire to help experimenter
Positive response to neutral conditions
Self Image Motives Lead to:
Positivity bias: I am better than others Normative bias: What I do is normal, sane, correct. Distinctiveness bias: But I am also unique and exceptional "Will this experiment make me appear stupid, weird, yet boringly common?"
Evidence of Subject Self-Presentation Motives
* Will do meaningless tasks for long time, willingly. * Will do noxious tasks: poisonous snakes, hand in acid * Will do ethically unsound acts: shock others to death
Placebo Effects * 30%-40% of drug effect is due to placebo * Placebos reduce tumors, diabetic blood sugar, pain
* Neurological effect among depressants
Relevance to research? Subjects can be very suggestible. Can unconsciously comply with deduced purpose of research.
Cause: Cues from the experimenter, the experimental situation, confederates, other subjects, or other sources that inadvertently direct subjects' responses.
Demand Characteristics
Examples? * Clever Hans* Facilitated Communication
Deception Experiments
Good cover storyPiloting and debriefingIV and DV in separate settingsKeep subjects unaware of being in an experiment
Behavioral Measures
Advantages over verbal, self report measuresNon-obvious measures
Bias-reducing Designs
Post-test onlyFactorial designs
Bogus Pipeline
Techniques for Counteracting Demand
Sources of Experimenter Bias
* Men friendlier than women, all experimenters nicer to women * Experimenter reaction to Subject attributes * Subject reaction to Experimenter attributes * Experimenter's research goals, knowledge of hyp.
-- "smart" vs. "dumb" rats-- "smart" vs. "dumb" worms-- Neutral faces
Source of Bias
Experimenter is unintended stimulus to subject
Subject is unintended stimulus to experimenter
Experimenter’s goals, knowledge of hypothesis
Is Bias Random or Systematic?
Random
Random
Systematic
Experimenter Bias
Techniques for Minimizing Experimenter Bias
1. Naïve experimenters (NOT!)
2. Experimenters blind to subject condition, not to hypothesis
3. Two experimenters, each half-blind
4. Automated instructions
5. Run all conditions at once
6. Experimenter blind to one variable in factorial design
7. Separate experimenter for each subject
8. Experimenter blind to incoming data
9. Combine techniques, above.
Confederate Race
Confederate Temperament
Friendly Unfriendly
Black Black/Friendly Black/Unfriendly
White White/Friendly White/Unfriendly
Experimenter Blind to One Factor in Factorial Design
Expt’r had to know confederate race
Could be blind to confederate temperament
Time Perspective Types
Future Oriented Decisions about how to act are influenced by considerations of future consequences. Long-term concerns are “real” and compelling to future oriented people. They “see” further out into the future.
Present Oriented Focus more on concrete reality of the immediate present. More likely to get sucked into the moment, and think less about long-term consequences. The see less far into the future, but may see the present in greater detail.
0
10
20
30
40
50
60
70
First Study Middle Studies Final Study
Nu
mb
er
of
Da
ys
Futures, Female
Futures, Male
Presents, Female
Presents, Male
Time Perspective and Subject Sign-upsHarber, Zimbardo, & Boyd, 2003
First Third of Term
2.57
0.79
1.29
0.33
Middle Third of Term 1.03 0.78 1.08 1.10
Female
Future
(n = 102)
Male
Future
(n = 75)
Female
Present
(n = 86)
Male
Present
(n = 112)
Final Third of Term 0.39 1.45 0.75 2.05
Odds ratios: Likelihood of sampling time orientation/ gender groupings during the 1st, 2nd, or 3rd of term.
1. Studies done early in term will have disproportionate numbers of future oriented women, studies done toward the end of the term will be disproportionately represented by present-oriented men.
2. Longitudinal studies may systematically lose more data (due to tardiness, etc.) from present oriented subjects than from future oriented subjects.
Time Perspective Differences—So What?
OK, so what's the big deal?
Time orientation might interact with research question, and bias results in unexpected ways.
Study originally done at one time in the term may not replicate if second study done later in term.
How Do Cows Get Milk? A Critique of Eve’s H2O,M Study
What is the research question? Is it clearly stated?
What is the hypothesis?
What is conceptual IV Fluid deprivation
What is empirical realization of IV? Milk cow dry, prevent drinking
What is dependent variable? Amount of milk produced at retest
Results Milk IS produced despite absence of of drinking!!!
Hypothesis confirmed?
Evidence of bias (demand?)
Alternative explanations?
Cows extract milk from air
YesNo
??????