Transcript Research Methods

The Need for
Science/Research
and
Research Methods
Chapter 1
Why we need Psychological
Science and Research
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Three reasons: 1. Intuition, 2. Hindsight Bias , 3.
Overconfidence
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Intuition = gut instinct
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Hindsight Bias = after you find out the outcome you
believe you knew the outcome all along
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That feeling inside of you telling you something is right or wrong
Examples: Columbia Disaster, Gulf oil spill, Man on the
moon(1969)
Overconfidence = thinking we know more than we do
about something; tend to be more confident than correct
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Examples man will never reach the moon(1957),”[Ronald]
Reagan doesn’t have the presidential look.” 1964, “Heavier than
air flying machines are impossible.” 1895
The Scientific Attitude and
Critical Thinking
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The scientific attitude
includes being curious,
skeptical and humble
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Explore, ask questions and
be willing to make or admit
mistakes
Accepting those three
characteristics allows one
to think critically
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Critical thinkers:
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Are open minded
Can live with uncertainty
Distinguish fact from
opinion; rely on science
rather than personal
experience
Realize the world is
complex; don’t over
simplify
View all available evidence
before reaching a
conclusion
The Scientific Method
Research Methods
Descriptive Method
Descriptive Method
 Observe,
collect, record data
 Describes but does not explain
 Easy to collect data
 Little or no control over variables, biases
and behaviors
 Three types
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Naturalistic observation, survey method, case
study
Naturalistic Observation
 Watching
and recording the behavior of an
organism in their natural environment
 Only describes the behavior
 Ex: Counting the number of people who
wear hats on a college campus
Survey Method
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research asks a representative sample (target group) of
people oral or written questions
 to find out about their attitudes, behaviors, beliefs,
opinions, and values.
 mail, face-to-face, by telephone, and the Internet
 Standardized, Inexpensive, replicable, large amount of
data quickly
 Describes doesn’t explain
 Ex: Student survey of risky behavior
Case Study
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detailed in-depth investigation of a single case
concerning a person, a family, an organization,
or an event.
detailed in-depth information
Can lead to a hypothesis for further study
Doesn’t explain, cannot be replicated, reliability
and validity are in question
Ex: effects of smoking on one individual
Experimental Method
Experimental Research
 Manipulation
and control of variables
 Identifies cause and effect
 Allows researcher precise control over
variables
 Ethical concerns, practical limitations,
artificiality, uncontrolled variables, biases
Steps for Experimentation
1) Theory - idea
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Sugar rots your teeth
2) Hypothesis/Operational Definition –
testable, measurable, verifiable
- Eating one bowl of sugar cereal every
morning rots your teeth
3) Variables
-Independent Variable (IV): manipulated variable
(types of cereal, amount of cereal )
- Dependent Variable (DV): actual outcome
(rotten teeth)
- Confounding Variable: any variable other
than the IV that could effect the outcome
4) Groups
- Control Group: does not receive treatment
(Placebo)
- Experimental Group: receives treatment
(cereal)
How groups are selected
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Population
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People that the sample is drawn from
• Ex: Swampscott High School
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Sample
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Subjects drawn from a particular population; target
group
• Ex: 9th grade boys
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Random Sample
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Randomly choosing from a population
• Ex: picking every 10th student who walks through the door
Control Measures
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Single Blind
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Controls subjects awareness
Researcher knows who is receiving active drug and
who is receiving placebo
Researcher can influence results
Double Blind
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Controls both subject and researchers awareness
Third party controls distribution
Less bias
More scientific
Hypothesis: Drinking Vodka causes aggressive behavior
Drink
Belief
Belief
Vodka Tonic
Believed drinking Vodka
Believed drinking Tonic
Water
Tonic Water
Believe drinking Vodka
Believed drinking tonic
water
Behavior
More aggressive
Behavior
Less aggressive
Conclusion: Belief affected behavior more than actual drink
Correlation Method
Correlation
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Correlation Research
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Statistical analysis of relationships between variables
Identify relationships and how well one variable
predicts another
Helps clarify relationships between variables that
can’t be examined by other methods and allows
prediction
Does not allow researchers to identify cause and
effect relationships
Correlation
causation
Types of Correlation
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Perfect
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Positive
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When both factors go up
(left-right)
0 - +1.0
Negative
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Rarely occurs
When one factor goes up
and the other goes down
(right – left)
0 - -1.0
Zero
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No relationship
Statistical Measures
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Mean (average) =
 Median (middle) =
 Mode (most frequent)=
 Range (difference between hi/lo) =