Transcript Overview - People Server at UNCW

Overview
• Intro: fact and fiction
• What is science?
• What Science is not
– Stereotypes
– Myths
• Assumptions of
science
– Empricism
– Determinism
– parsimony
• Methods of Science
– Objectivity
– control
– Operational definition
Which technique would you choose
to study…say
• Human sexual intimacy?
Psychological Phenomena that are:
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Private
Sensitive
Rare
internal
SELF-REPORT
approaches…….SURVEYS
• What do we want to know
• Construction
– Questions
– responses
• Who do we want to know about
-Administration
– sampling
Survey construction and reactivity
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Topic areas
Confidential and Anonymous
Instructions-honest and accurate
Inclusion of “lie-detectors?”
– Reverse ordered questions
– Catch questions
– etc
Other factors that may affect reactive
responses
• Length
• Clarity of questions/grammar
– Jargon, acronyms,
– “how effective is the SSC in meeting your
campus needs?”
– “Does the student newspaper obfuscate the
truth?”
Avoid Leading Questions
• “do you agree that grades should be
abolished in public schools?”
• Most doctors feel that a high fiber diet is
healthy. How strongly do you agree or
disagree?”
Avoid emotionally loaded or
“charged” words or biased wording
• “should “junkies” be sent to jail or given
treatment?”
• “charged” words?.....Lie, hate, jealous,
promiscuous, etc…
• Do you think pornography is vile and
disgusting?
Avoid “appeals to prestige.”
• Lower, middle or upper class
Avoid double-barreled questions; 2
questions in one
• Ham and eggs?
• Sent to jail and given therapy?
• etc
Don’t assume knowledge
• Should society adopt the medical or the
moral model to deal with drug addicts?
SURVEY RESPONSES
• Closed vs open
DO you think marijuana use is
harmful
• Yes
• No
• What is the problem here?
Rating scales
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Number of points?
Anchors
Odd or even?...forced choices
Likert type
Psychological scales
• Sets of questions that collectively measure
an attribute, attitude, disposition, etc…
Population vs. sample
Sampling: representation vs bias
• Identification of target population?
• Approach and demeanor of researcher
– Simple random sampling
– Stratified random sampling
– Proportionate sampling
Sample Size?
Survey Administration
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Paper
Interview
Telephone
Mail
Computer
– Return rate issues?
Final comments on Self-report
studies
• ISSUES OF
– Reactivity vs Control
– Knowledge
– Accuracy
– Motivation
– Interpretation…relationship to behavior???
Descriptive approaches:
CORRELATION
• Relatedness of different measures
• Allows prediction
Correlational studies may reveal interesting
relationships between different variables
• E.G.
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Traffic Accidents and time of day?
Age and Aggression
Internet Dating and Personality factors
Drug use and social attitudes
Eye contact and “liking”
The Limits of correlation: 3rd
Variables
Let’s consider these ideas:
Does Nicotine cause addiction?
Does Nutra-sweet cause cancer?
Does Social romantic attraction cause/lead to social
affiliation?
3rd variables
Does Nicotine cause addiction?
-personality? Stress?
Does Nutra-sweet cause cancer?
-Other food substances, genetics, exposure to
environmental hazards etc..
Does Social romantic attraction cause/lead to social
affiliation?
-liking? Loneliness? Politeness? Intellectual
interest? Other motivations…
Directionality is another problem in
this respect
Does Nicotine cause addiction?
-could addictive personalities lead to tobacco use
Does Nutra-sweet cause cancer?
-Could predisposition for cancer lead to higher
use of certain substances?
Does Social romantic attraction cause/lead to
social affiliation?
Could affiliation lead to attraction?
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• Correlations are Descriptive
• they do not control for 3rd Variables
• or Directionality
• Therefore Scientists refrain from making
causal conclusions based on Correlation
evidence.
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The Aspartame Controversy
While questions about saccharin may persist, the safety of another artificial
sweetener, aspartame, is clear cut, say FDA officials. FDA calls aspartame, sold
under trade names such as NutraSweet and Equal, one of the most thoroughly tested
and studied food additives the agency has ever approved. The agency says the more
than 100 toxicological and clinical studies it has reviewed confirm that aspartame is
safe for the general population.
This message would not necessarily be apparent to consumers surfing the Internet,
especially those who use Web-based search engines to find information about sugar
substitutes or artificial sweeteners. Websites with screaming headlines and wellwritten text attempt to link aspartame consumption to systemic lupus, multiple
sclerosis, vision problems, headaches, fatigue, and even Alzheimer's disease. One
report distributed nationally over e-mail systems claims that aspartame-sweetened
soft drinks delivered to military personnel during the Persian Gulf War may have
prompted Gulf War syndrome.
No way, says FDA, along with many other health organizations such as the American
Medical Association. David Hattan, Ph.D., acting director of FDA's division of health
effects evaluation, says there is no "credible evidence," to support, for example, a link
between aspartame and multiple sclerosis or systemic lupus. Some Internet reports
claim that patients suffering from both conditions went into remission after
discontinuing aspartame use. "Both of these disorders are subject to spontaneous
remissions and exacerbation," says Hattan. "So it is entirely possible that when
patients stopped using aspartame they might also coincidentally have had remission
of their symptoms."
It is true, says Hattan, that aspartame ingestion results in the production of methanol,
formaldehyde and formate--substances that could be considered toxic at high doses.
But the levels formed are modest, and substances such as methanol are found in
higher amounts in common food products such as citrus juices and tomatoes.
So why use correlation rather than
experimentation?
• Allows study of non-manipulatable
variables
– Gender, drug use, etc
– May identify or discover new relationships
– Suggests possible causal relationships