Transcript Research Methods FOR ASSESSMENT.ppt

Research Methods
Critical thinking = actively
questioning statements rather than
blindly accepting them
Case study
• = in-depth study of one individual
– Good for RARE cases
• Serial killers (Ted Bundy, John Wayne Gacy, Jeffrey
Dahmer)
• Rare diseases (fatal familial insomnia)
– Problem
• Can’t generalize
• Can’t say what caused the problem through a case
study only
Naturalistic observation
= observe subject/individual(s) in natural setting
– One-way mirrors, cameras
• Useful for DESCRIBING behavior
– Used with animals in the wild
• E.g., watch and record members of a Koala family in
Australia
Surveys
= answering questions
• E.g., political polls - Who will you vote for?
• Sexual behavior – do you cheat on your
significant other?
• Problem
– Not everyone is honest
– Can you just invite people who want to answer
the questions?
– Can you just put it on the internet?
• Ideally, obtain a representative sample
=people who mirror the larger population.
– E.g., if doing a study about college students,
include
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Students of all ages
Students who work
Males and females
Who else can you think of?
Try to get a representative sample whenever you can
(for surveys, experiments, etc)
The Experiment
• = SCIENTIFIC / EMPIRICAL
– Empirical = the result of observation, measurement,
and experimentation
• Develop a hypothesis
= a specific, testable prediction about what you think will
happen in your study
e.g., adolescents are more likely to smoke if their
parents smoke
e.g. People who take Prozac will experience ________
depression (more / less?)
• The ONLY way to determine cause and effect*
• First, obtain informed consent
– E.g., this medication may not benefit you, may
harm you…sign here _____________
– Choose your independent and dependent
variables
• Independent variable = the variable that the
experimenter manipulates/changes around
• Dependent variable = the variable that is measured at
the end of the experiment
Exercise: Design a study on the
Effect of Prozac on Depression
– N= 100
– Control group = group that receives no treatment
– Placebo = an inactive substance or fake treatment
which is used as a control technique
• What is your IV and DV?
• What is your hypothesis?
• (hypothesis = a testable prediction about the
conditions under which a particular behavior or mental
process may occur)
• What are your confounding variables?
(Variables that could interfere with your
hypothesis)
• If findings are “statistically significant,” your
hypothesis has been supported.
• E.g., People who took Prozac were less depressed.
• E.g., People who talk on cell phones are more likely to
get into accidents. (It happens significantly more often)
• Statistical significance does NOT mean your information
in necessarily useful or practical
– A real study shows that people with spider phobias are afraid
to touch spiders. (They got statistical significance/support for
hypothesis, BUT they didn’t have to do the study to figure
that out!)
• In your study, include operational definitions
– Precise
– Objective
– Measurable
– Example: Teaching a rat to bar press
Correlational Studies
• Correlation = a relationship between 2
variables
• Positive correlation = as 1 variable ↑, the
other ↑
– E.g., studying and grades
• Negative correlation = as 1 variable ↑, the
other variable ↓
– E.g., heavy partying and grades
• Correlation coefficient = describes the
strength of the relationship.
• Ranges from -1 to 1
1 OR -1 = strongest, perfect relationship. 1 or -1
signifies 100%.
e.g., the size of a balloon and the amount of air
in a balloon (positive or negative?)
0 = NO RELATIONSHIP
• Correlational research may reveal
– The ability to predict one variable from another
– A reliable relationship between variables
– A numerical description of the strength between 2
variables
• BUT CANNOT SAY THAT ONE CAUSES THE
OTHER!!
– E.g., ice cream sales and crime