9/13/13 Aim: How and why do
psychologists produce valid
research?
• Do Now: Fill out the survey.
1
Aim: How do biases contaminate
our everyday judgments?
• Do now: I need 5 volunteers – raise your
hand if you want to volunteer.
» Truth/lie
»
•
•
•
•
% of your confidence 50 guess
100 % totally sure
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2
3
4
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Overconfidence
Sometimes we think we
know more than we
actually know.
How long do you think it
would take to unscramble
these anagrams?
People said it would take
about 10 seconds, yet on
average they took about 3
minutes.
Anagram
WREAT
WATER
ETYRN
ENTRY
GRABE
BARGE
3
Hindsight Bias
Hindsight Bias is the “I-knew-it-all-along”
phenomenon.
After learning the outcome of an event, many
people believe they could have predicted that very
outcome. We only knew the dot.com stocks would
plummet after they actually did plummet.
Show clip.
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Confirmation Bias
• We seek to find information that confirms
what we already know.
• How does the Seinfeld clip show
confirmation bias? Explain.
5
False Consensus Effect
• The tendency to overestimate how much
other people agree with you. There is a
tendency for people to assume that their
own opinions, beliefs, preferences, values
and habits are 'normal' and that others
also think the same way that they do.
• Show clip
6
Aim: What are the Goals of
Research • Do Now: copy the statements (leave room)
– Placebo
– Explain about lie detectors
– Explain Hite research
– What is correlation
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9/15 Aim: What are the 3 goals
of psychological research?
• Do Now: Set up an experiment to
determine if viewing Spongebob causes
decreased ability to focus in academic
tasks in young viewers
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9/19 Aim: How do experiments, powered by
random assignment, clarify cause and effect?
• Do Now: Identify the difference between
the following:
– Random sample
– Random assignment
– Also, what is the placebo effect?
– After the clip, answer “How does the clip show
a placebo effect?”
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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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Psychological Science
1. How can we differentiate between
uniformed opinions and examined
conclusions?
2. The science of psychology helps make
these examined conclusions, which leads
to our understanding of how people feel,
think, and act as they do!
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The Scientific Attitude
The scientific attitude is composed of curiosity
(passion for exploration), skepticism (doubting
and questioning) and humility (ability to accept
responsibility when wrong).
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Scientific Method
Psychologists, like all scientists, use the
scientific method to construct theories that
organize, summarize and simplify
observations.
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Research Observations
Research would require us to administer
tests of self-esteem and depression.
Individuals who score low on a self-esteem
test and high on a depression test would
confirm our hypothesis.
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Aim: What are the goals of
psychological research?
• 1. describe behavior
• 2. predict behavior
• 3. determine cause and effect
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Describe behavior has 3 tools
• Case Study
• Survey
• Naturalistic Observation
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Prediction has 1 tool
• Correlation
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Determine cause and effect has
one tool
• Experimentation
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Describe behavior – CASE STUDY
Case Study
A technique in which one person is studied in
depth to reveal underlying behavioral principles.
Advantages – get to know one person in depth
Disadvantage – cannot generalize findings to
population
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Describe behavior - Survey
A technique for questioning the self-reported
attitudes, opinions or behaviors of people
Advantages inexpensive, easy to collect data,
easy to generalize – used in conjunction with
correlations
Disadvantages – may not be honest, wording
effects may confuse people, may not be a
representative sample (Hite research)
Terms - representative, random sample,
generalize.
Social desirability bias – people answer how
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they think others want them to answer
Survey - disadvantages
False Consensus Effect
A tendency to overestimate the extent to
which others share our beliefs and
behaviors.
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Describe behavior - Naturalistic
Observation
Observing and recording the behavior of people/animals in
the wild and recording self-seating patterns in a multiracial
school lunch room constitute naturalistic observation.
Advantages – realistic data
Disadvantages – could interfere with behaviors, no control
like a lab
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9/18 Aim: What are positive and negative
correlations, and why do they enable prediction but
not cause-effect explanation?
• Copy Aim onto top of worksheet
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Correlation – used to predict
behavior
When we reveal a relationship between two
variables, the are correlated, used to predict
Advantages – allow for prediction, collect
data from surveys
Disads - does not mean causation
Correlation
coefficient
Correlation Coefficient is a
statistical measure of the
relationship between two
variables.
Indicates strength
of relationship
(0.00 to 1.00)
r = + 0.37
Indicates direction
of relationship
(positive or negative)
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Terms: Scatterplots
Perfect positive
correlation (+1.00)
Scatterplot is a graph comprised of points that are
generated by values of two variables. The slope of
the points depicts the direction, while the amount
of scatter depicts the strength of the relationship.
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Perfect positive
correlation (+1.00)
Perfect negative
correlation (-1.00)
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• If two things are positively correlated, the
presence of one predicts the presence of
the other
• In contrast, a negative correlation means
that the presence of one thing predicts the
absence of the other
• When no exists between two variables NO
correlation exists.
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• Correlations can be either strong or weak.
• The strength of a correlations is expressed
by a number called correlation coefficient
• -1 and + 1 are both very strong . The
number 0 denotes a weak relationship.
• Describe a r= -.12
_______________________
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Scatterplots
Perfect negative
correlation (-1.00)
No relationship (0.00)
The Scatterplot on the left shows a negative correlation,
while the one on the right shows no relationship between
the two variables.
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Data
Data showing height and temperament in people.
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Scatterplot
The Scatterplot below shows the relationship
between height and temperament in people. There
is a moderate positive correlation of +0.63.
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Correlation and Causation
or
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Illusory Correlation
The perception of a relationship where no relationship
actually exists.
Ex: sugar makes children hyperactive
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Order in Random Events
Given random data, we look for order and
meaningful patterns.
Your chances of being dealt either of these hands is
precisely the same: 1 in 2,598,960.
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Order in Random Events
Given large numbers of random outcomes, a few
are likely to express order.
Jerry Telfer/ San Francisco Chronicle
Angelo and Maria Gallina won two
California lottery games on the same day.
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Aim: How do we use
Experimentation To determine
Cause and Effect
Like other sciences, experimentation is the
backbone of psychology research. Experiments
isolate causes and their effects. Experiments (1)
manipulate factors that interest us, while other
factors are kept under (2) control
Advantages – controlled environment
Disadvantages – confounding variables –
variables the may affect our data
Terms – assignment of group members - control/experimental, double blind, blind, placebo,36
experimenter bias
Exploring Cause & Effect
Many factors influence our behavior..
Effects generated by manipulated factors isolate
cause and effect relationships.
Advantages – controlled environment
Disadvantages – confounding variables,
experimenter bias
Terms – assignment, random, double blind, blind,
placebo, control group, experimental group
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Independent Variable
An Independent Variable is a factor manipulated
by the experimenter. The effect of the independent
variable is the focus of the study.
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Dependent Variable
A Dependent Variable is a factor that may change
in response to an independent variable. In
psychology, it is usually a behavior or a mental
process.
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Operational Definitions
• Clearly define your variables so that others
can clearly replicate your research and get
the same results (reliable)
– Example: watching 9 minutes of Sponge Bob
– Independent variable operationally defined
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Example
•
•
•
•
Independent Variable – special juice
Dependent Variable – worker productivity
Exp Group – juice
Control – no juice
• Always make your experimental group the
Independent variable and it will be right!
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Megan wants to test 3 different treatments on the
cure of phobias. Subjects were exposed to one of
the 3 possible treatments for a period of 3 months
and are then tested for a reaction to their fear.
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Evaluating Therapies
Double-blind Procedure
In evaluating drug therapies, patients and
experimenter’s assistants should remain
unaware of which patients had the real
treatment and which patients had the placebo
treatment.
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9/20/13 What are the terms
associated with good research?
• On the bottom of yesterdays sheet, match
the terms.
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Research Process
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1. It all starts with a THEORY
• Explanation using an integrated set of
principles that organize and predicts
observations and ideas
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2. Population
• all the cases in a group, from which
samples may be drawn for a study
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3. Valid
• Does the research measure what it
intends to measure
– Ex: If you are trying to measure for
intelligence but actually ask questions
regarding physical tasks (jumping up and
down, how fast you can run)
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4. Replication
• repeating the essence of a research study,
usually w/ different participants in different
situations, to see whether the basic finding
extends to other participants and
circumstances
– Need to have clear operational definitions to
replicate
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5. Critical Thinking
Critical thinking does not accept arguments and
conclusions blindly.
It examines assumptions, discerns hidden values,
evaluates evidence and assesses conclusions.
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6. Reliable
• Through replication can we support the
same or similar results again and again
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7. Hypothesis
A Hypothesis is a testable prediction, often
prompted by a theory, to enable us to
accept, reject or revise the theory.
Ex: People with low self-esteem are more
likely to feel depressed. (correlation)
Viewing aggressive television creates causes
aggressive behavior.(cause and effect)
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8. Operational definition
• Clearly define your variables so another
researcher can replicate your experiment
and or findings
– Defining clearly your independent and
dependent variables
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9.Generalize
• The ability to apply your research findings
in your sample to the entire population
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10. Sample
• group that fairly represents a population
because each member has an equal
chance of inclusion in the study
– Best is random sample
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Hawthorne Effect – aka
observer effect
• Increasing
• decreasing
• The change in behavior that occurs
when people know they are being
watched.
• Cartoon – The tribe members are
more advanced than they appear,
they are putting on a performance for
the anthropologists (study cultures –
present and past - primitive)
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Answers to MC Questions (no
stats)
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•
•
•
•
•
•
1.A
2. C
3.C
4.D
5. D
6.D
7.D
8.B
9. C
10.B
11. D
12.D
16.D
19. D
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9/25/13Aim: How can we describe data with
measures of central tendency and variation?
Do Now: What is misleading about the two
sets of data?
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Describing Data
A meaningful description of data is important in
research. Misrepresentation may lead to
incorrect conclusions. Theses are histograms
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Histogram – show us data
distribution
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Frequency polygon –
distribution of data but without
bars
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Measures of Central Tendency –
neatly summarize the data, tell
about the average
Mode: The most frequently occurring score in
a distribution.
5,6,7,7,7,8,8,9,9,10 – mode is 7
Mean: The arithmetic average of scores in a
distribution obtained by adding the scores
and then dividing by the number of scores
that were added together. VERY
SENSITIVE – affected by extreme scores
5,6,7,7,7,8,8,9,9,10 – mean 7.5
Median: The middle score in a rank-ordered
distribution. 5,6,7,7,7,8,8,9,9,10 – median
7.6
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Measures of Central Tendency
A Skewed Distribution
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So…which measure of central
tendency is most affected by
extreme scores??
• Mean
• Let’s find out how – handout with extreme
scores on the bottom
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Positive Skew
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Negative Skew
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Measures of Variation – how
similar or diverse the scores are
Range: The difference between the highest and
lowest scores in a distribution; crude range
Largest range will have largest standard deviation
(MOST affected by extreme scores)
Standard Deviation: A computed measure of how
much scores vary around the mean; how do they
deviate from each other (square root
Of the variance)
Variance: how the scores deviate about the mean,
smaller variance and sd mean representative data,
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less disperse data. Data is similar
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Which measure of variation is
most affected by extreme
scores?
• The range (difference of low to high)
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What kind of data suggests that
scores are similar?
• Scores with low variance and standard
deviation
• Data that is similar is better. Why?
– You can generalize it to the population
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Standard Deviation
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Variance
• Is the square of the standard deviation
• In the first example, the standard
deviation was 5, the variance is 25.
• In the second example, the standard
deviation was 15, the variance is 225
• Large variance means the data is widely
spread about the mean, so the data is not
similar
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Explain what these mean
If a set of data is has a ….
• Small standard deviation
– Range is small and data is similar to average
• Large standard deviation
– Range is large and data is different from
average
• Small variance
– Range is small and data is similar to average
• Large variance
– Range is large and data is different from
average
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Making Inferences
A statistical statement of how frequently an
obtained result occurred by experimental
manipulation or by chance.
Are the results real or not?
How similar are your scores to what the general
population would have scored?
What do you think? Do we want our results to
because of our experiment or because of chance?
Pick one and explain why.
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Making Inferences
When is an Observed Difference Reliable?
1. Representative samples are better than biased
samples.
2. Less variability and standard deviation are
observations are more reliable than more
variable ones.
3. More cases are better than fewer cases.
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Making Inferences
When is a Difference Significant?
When sample averages are reliable and the
difference between them is relatively large, we say
the difference has statistical significance.
For psychologists this difference is measured
through alpha level set at 5 percent. If p=.05 (95%)
or less
This number means we are 95% confident our
results are due to our experiment and NOT DUE
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TO CHANCE
Answers to MC stats questions
•
•
•
•
•
•
•
13. A
14.D
15. B
16 D
17.C
18.C
20.A
•
•
•
•
•
•
•
•
•
Matching
1.i
2.f
3.l
4.j
5.e
6.b
7h
8g
•
•
•
•
•
•
9c
10a
11d
12m
13k
14n
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9/24/12 Aim: What are the ethics
involved in conducting research?
• Do Now: Look at your informed consent
form - What do you think is unethical
about it? List.
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Ethics - IDCARD
• Informed Consent – must know they are
involved and give permission
• Deception – cannot trick participants about the
nature of the research, might invalidate informed
consent
• Coercion – cannot dupe or force them to
participate in the study
• Anonymity – must not reveal information about
individuals by name
• Risk – no significant physical and mental risk
• Debriefing – must tell them the purpose of the 82
study and contact them after with results
Here’s a question for you…
• When is it permissible for a psychologist to
share a client’s test scores with another
person?
When the client provides written permission to share results
(informed consent)
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What are the 3 guidelines for
experimenting on animals?
All researchers who deal with animal research are
required to follow ethical guidelines in caring for
these animals
1.Clear purpose
2. Care for animals (alaa rocks)
3. Least amount of risk
What is the difference between animals and mans?
Animals can be placed in greater harm than
humans
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• On a scale of 1-5, please rate how
accurate the personality assessment is.
• 1 – not accurate at all
• 2 –maybe a tiny bit accurate
• 3 – eh
• 4 – somewhat accurate
• 5- very accurate, this is totally me
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Barnum Effect (after PT Barnum)
• “There’s a sucker born every minute”
• Why are there so many 4s 5s?
• People believe positive statements
about themselves, more positive –
greater believability
• People are more willing to believe
something if it is from an authority
figure
• People believe if it is “uniquely
prepared for them”
• General, vague opposite statements
apply to all
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