Post on 14-Dec-2015
transcript
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Impression of Psychology With hopes of satisfying curiosity, many people listen to talk-radio counselors and psychics to
learn about others and themselves.
Dr. Crane (radio-shrink)
http://ww
w.nbc.com
http://ww
w.photovault.com
Psychic (Ball gazing)
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The Need for Psychological Science
Intuition & Common Sense
Many people believe that intuition and common sense are enough to bring forth
answers regarding human nature.
Intuition and common sense may aid queries, but they are not free of error.
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Limits of Intuition
Personal interviewers may rely too much on their “gut feelings” when
meeting with job applicants.
Taxi/ G
etty Images
The Need for Psychological Science
Psychologists, like all scientists, use the scientific method to
construct theories that organize observations and imply testable hypotheses
The Need for Psychological Science
Hindsight Bias we tend to believe, after learning an
outcome, that we would have foreseen it
the “I-knew-it-all-along” phenomenon Overconfidence
we tend to think we know more than we do
The Need for Psychological Science
Critical Thinking thinking that does
not blindly accept arguments and conclusions examines
assumptions discerns hidden
values evaluates evidence
The Amazing Randi--Skeptic
The Need for Psychological Science
Theory an explanation using an integrated
set of principles that organizes and predicts observations
Hypothesis a testable prediction often implied by a theory
The Need for Psychological Science
The Need for Psychological Science
Operational Definition a statement of procedures
(operations) used to define research variables
Example- intelligence may be operationally defined
as what an intelligence test measures
The Need for Psychological Science
Replication repeating the essence of a
research study to see whether the basic finding generalizes to other participants and circumstances
usually with different participants in different situations
Description
Psychologists describe behavior using case studies,
surveys, and naturalistic observation
Description
Case Study Psychologists
study one or more individuals in great depth in the hope of revealing things true of us all Is language uniquely human?
Description
Survey technique for ascertaining the self-
reported attitudes or behaviors of people usually by questioning a representative,
random sample of people Random Sample
a sample that fairly represents a population because each member has an equal chance of inclusion
Description
False Consensus Effect tendency to overestimate the extent
to which others share our beliefs and behaviors
Population all the cases in a group, from which
samples may be drawn for a study
Description
If marbles of two colors are mixed well in the large jar, the fastest way to know their ratio is to blindly transfer a few into a smaller one and count them
Description
Description
Naturalistic Observation observing and
recording behavior in naturally occurring situations without trying to manipulate and control the situation
Correlation Correlation Coefficient
a statistical measure of the extent to which two factors vary together, and thus how well either factor predicts the other
Correlation coefficient
Indicates directionof relationship
(positive or negative)
Indicates strengthof relationship(0.00 to 1.00)
r = +.37
Correlation
Scatterplot a graphed cluster of dots, each of which
represents the values of two variables the slope of the points suggests the
direction of the relationship the amount of scatter suggests the
strength of the correlation little scatter indicates high correlation
also called a scattergram or scatter diagram
Correlation
Perfect positivecorrelation (+1.00)
No relationship (0.00) Perfect negativecorrelation (-1.00)
Scatterplots, showing patterns of correlations
Scientific Approach to Behavior
Experimental Research
Descriptive/Correlational Research
Positive CorrelationHigh scores on X are associated with high scores on Y,and low scores on X are associated with low scores on Y.
# of CigarettesSmoked
X
Blood PressureReading
Y
# of Cigarettes Smoked
X
Blood Pressure Reading
Y
EthicsStatistics andResearch
EvaluatingResearch
Negative CorrelationHigh scores on X are associated with low scores on Y,and low scores on X are associated with high scores on Y.
Amount ofCocaine Ingested
X
# of HoursSlept
Y
Amount ofCocaine Ingested
X
# of HoursSlept
Y
Scientific Approach to Behavior
Experimental Research
Descriptive/Correlational Research
EthicsStatistics andResearch
EvaluatingResearch
Negative Correlation Positive Correlation
Strength of Relationship
Increasing Increasing
High Moderate Low HighModerateLow
1.00.90.80.70.60.50.40.30.20.100-.10-.20-.30-.40-.50-.60-.70-.80-.90-1.00
Scientific Approach to Behavior
Experimental Research
Descriptive/Correlational Research
EthicsStatistics andResearch
EvaluatingResearch
Scientific Approach to Behavior
Experimental Research
Descriptive/Correlational Research
EthicsStatistics andResearch
EvaluatingResearch
.05 level of significance
CorrelationHeight and Temperament of 20 Men
123456789
10
11121314151617181920
80636179746962757760
64767166737063716870
75666090604242608139
48697257637530578439
SubjectHeight in
Inches Temperament SubjectHeight in
Inches Temperament
Correlation
Scatterplot of Height and Temperament
55 60 65 70 75 80 85
959085807570656055504540353025
Temperamentscores
Height in inches
CorrelationThree Possible Cause-Effect Relationships
(1)Low self-esteem
Depression
(2)Depression
Low self-esteem
Low self-esteem
Depression
(3)Distressing events
or biologicalpredisposition
could cause
could cause
could cause
or
or
and
Illusory Correlation
Illusory Correlation the
perception of a relationship where none exists
Conceive Do not conceive
Adopt
Do notadopt
disconfirming evidence
confirming evidence
disconfirming evidence
confirming evidence
Two Random Sequences
Your chances of being dealt either of these hands is precisely the same: 1 in 2,598,960.
Experimentation
Experiment an investigator manipulates one or
more factors (independent variables) to observe their effect on some behavior or mental process (the dependent variable)
by random assignment of participants the experiment controls other relevant factors
Experimentation Placebo
an inert substance or condition that may be administered instead of a presumed active agent, such as a drug, to see if it triggers the effects believed to characterize the active agent
Double-blind Procedure both the research participants and the
research staff are ignorant (blind) about whether the research participants have received the treatment or a placebo
commonly used in drug-evaluation studies
Experimentation
Experimental Condition the condition of an experiment that
exposes participants to the treatment, that is, to one version of the independent variable
Control Condition the condition of an experiment that
contrasts with the experimental treatment serves as a comparison for evaluating the
effect of the treatment
Experimentation
Random Assignmentassigning participants to experimental and control conditions by chance
minimizes pre-existing differences between those assigned to the different groups
Experimentation Independent Variable
the experimental factor that is manipulated
the variable whose effect is being studied Dependent Variable
the experimental factor that may change in response to manipulations of the independent variable
in psychology it is usually a behavior or mental process
Experimentation
Statistical Reasoning
Our Brand Brand BrandBrand X Y Z
100%
99
98
97
96
95
Percentagestill functioningafter 10 years
Brand of truck
Statistical Reasoning
Our Brand Brand Brand Brand X Y Z
100%
90
80
70
60
50
40
30
20
10
0
Percentagestill functioningafter 10 years
Brand of truck
Statistical Reasoning Mode
the most frequently occurring score in a distribution
Mean the arithmetic average of a distribution obtained by adding the scores and then
dividing by the number of scores Median
the middle score in a distribution half the scores are above it and half are
below it
Statistical Reasoning
A Skewed Distribution
15 20 25 30 35 40 45 50 90 475 710
70
Mode Median Mean
One Family Income per family in thousands of dollars
Statistical Reasoning
Range the difference between the highest and
lowest scores in a distribution Standard Deviation
a computed measure of how much scores vary around the mean
Statistical Significance a statistical statement of how likely it is that
an obtained result occurred by chance
Frequently Asked Questions about Psychology
Can laboratory experiments illuminate everyday life?
Frequently Asked Questions about Psychology
Does behavior depend on ones culture? Culture--the enduring
behaviors, ideas, attitudes, and traditions shared by a large group of people and transmitted from one generation to the next
Frequently Asked Questions about Psychology
Does behavior vary with gender?
Frequently Asked Questions about Psychology
Why do psychologists study animals?
Is it ethical to experiment on animals?
Is it ethical to experiment on people?
Frequently Asked Questions about Psychology
Is psychology free of value judgments?
Frequently Asked Questions about Psychology
Is psychology potentially dangerous?
1 Psychology is Empirical
2 Psychology is Theoretically Diverse
3 Psychology Evolves in a Sociohistorical Context
Psychology Today: Vigorous and Diversified
Seven Unifying Themes
PersonalApplication
Psychology’s Early History
Psychology’s Modern History
4 Behavior is Determined by Multiple Causes
5 Behavior is Shaped by Cultural Heritage
6 Heredity and Environment Jointly Influence Behavior
7 People’s Experience of the World is Highly Subjective
Psychology Today: Vigorous and Diversified
Seven Unifying Themes
PersonalApplication
Psychology’s Early History
Psychology’s Modern History