To be human is to be curious…
O EVERYDAY we say:
O “why did she say that?”
O why did he behave that
way?”
O Psychologists say:
“What is the use of SAT
scores?
O How do we diagnose ADHD?
O Does specific gene cause
obesity?
O
O After asking these questions
psychologists must decide
which research technique or
procedure will help them to
best answer their question.
Need for Psychological Science
O
O
O
O
O
Most people think that psychology
merely documents and dresses in
jargon of what people already know
Some people think human intuition is
where we should put our trust and faith
in…
HOWEVER we operate on two levels,
conscious and unconscious, and most
of the time we are operating
automatically on autopilot
Psych experiments have shown that
people overestimate their lie detection
accuracy, eyewitness testimony, their
risks, predictions and many other
things
Autopilot…Autopilot… as you will
learn, our thinking, memory, &
attitudes operate largely on automatic
processing, (unconsciously)
Hindsight Bias: I knew it all
along phenomenon
O
O
We find it so easy to seem insightful
when drawing the bull’s eye after the
arrow has struck
O Ex: world trade center
Finding that something happened
makes it seem inevitable, a tendency
we call hindsight bias (I knew it all
along phenomenon)
O Ex: Romantic Attraction study
Demonstrated: giving half
member of a group some bogous
“psychological finding” and give
the other half the opposite result
 nearly all regard this ”true
finding” as unsurprising common
sense!!
Pg. 17
Why we need psychological
science….
O
O
these errors in our recollections
that show why we need
psychological science…
O Just asking people how they
feel or acts as they did can
sometimes be misleading
because common sense
describes what happened
not what will happen
O Hindsight bias is widespread
studies reported it is found in
various countries an among
both children and adults
We are all behavior watchers and it
would be surprising is psychology’s
findings has not been forseen
(according to those who say their
grandma already knew that)
Overconfidence
O As humans we tend
to be overconfident
O We tend to think we
know more than we
do
O When asked how
sure we are of our
answers to factual
questions we tend to
be more confident
that correct
O Ex: WREATWATER
What do you think?
O How many seconds
do you think it
would take you to
solve these?
O WREAT
O ETRYN
O GRABE
O OSCHA
OVERCONFIDENCE
Hindsight seems so obvious that people become over
confident
Goranson 1978 asked people to
unscramble the words, average took 3
minutes to unscramble but they think they
would have the solution in only 10 seconds
O
Average answer = 10 seconds, average
solved = 3 minutes
Once people know the answer hindsight bias
seems obvious so much that we become over
confident
Point to remember: hindsight bias and
overconfidence often lead us to overestimated
intuition  BUT scientific inquiry can help us sift
reality from illusion
O
O
O
O
SCIENTIFIC RESEARCH CAN SHIFT FORM
ILLUSION TO REALITY
3 component of Sci. Attitude:
The empirical approach
O
O
3 main components:
Curiosity: passion to explore
and understand without
misleading or being mislead
O
O
O
Skepticism: curious skepticism
not cynical, open but not
gullible:
O
O
O
Ex: does it work? When put to
the test can its predictions be
confirmed?
EX: James Randi
What do you mean? How do you
know?
Putting claims to the test
Humility: awareness to our own
vulnerability to error and
openness to surprises and new
perspectives:
O
O
What matters are the truths
nature reveals not opinions
“the rat is always right”
How to Think Critically
O
O
O
O
O
Critical thinking:
Thinking that does not blindly
accept arguments or conclusions
scientific attitude prepares us to
think smarter
examines assumptions, discerns
hidden values, evaluates evidence,
and assess conclusions
EX:
O
how do they know that?
O
What is this persons agenda?
O
Is the conclusion based on
anecdote and gut feelings or
evidence?
O
Does the evidence justify a
cause and effect conclusions?
O
What alternative explanations
are possible?
Psychological Science
1.
2.
How can we differentiate between
uninformed opinions and examined
conclusions?
The science of psychology helps make
these examined conclusions, which
leads to our understanding of how
people feel, think, and act as they do!
The science of psychology
O Scientific Method:
O
is an approach to
gathering information and
answering questions so
that errors and biases are
minimized
O In psychology conclusions
are based on data that
support predictions; data
can come from
experiments, surveys, case
studies.
1
. Observe the
behavior/Identify the
problem or questions
(describe)
2. Formulate a
hypothesis (explain)
3. Collect data through
observation and
experimentation
(predict)
4. Analyze the data
collected
5. Formulate a theory
(control/influence)
Theories & Hypotheses
O
theory:
O
O
explains though an integrated set of principles that organizes observations and
predicts behaviors or events
A theory simplifies by organizing and simplifying
O
O
O
Hypotheses:
O
O
O
O
Good theory produces testable predictions call hypotheses  Testing and rejecting
or revising theories allows these predictions to give direction to research; they
specify what result would support the theory and which would disconfirm it
Can lead to subjective observations: seeing what we expect
People with low self-esteem are apt to feel more depressed.
Operational Definitions:
O
Used to check on biases of psychologists; thus they will report their research with
precise operational definitions of procedures & concepts
O
O
O
Ex: facts & observations & their links
For example, low self-esteem contributes to depression.
Ex: “hunger”  reported as “hours without eating”
Generosity  money donated
Replication:
O
Operational definitions allow for researches to recreate the study  if replication
studies produce similar results then our confidence in finding reliability grows
Research Observations
Research would require us to administer
tests of self-esteem and depression.
Individuals who score low on a selfesteem test and high on a depression test
would confirm our hypothesis.
Research Process
methods of research
O Descriptive Methods:
O Includes: case
studies, surveys, &
natural observations,
correlations
O Correlational methods:
O Associations of
different factors
O Experimental methods:
O Manipulating factors
to find cause & effect
What is going on in this picture?
We cannot say exactly, but we can
describe what we see.
Thus we have…..
Descriptive Research
O Any research that observes and records.
O Does not talk about relationships, it just describes.
Naturalistic Observation

A descriptive method that
observes & records behavior in
natural occurring settings
without trying to manipulate or
control the situation

Ex: watching chimps in the
jungle to videotaping parent
child interactions, recording
seating patterns in lunch room
Only describes behavior does
not explain it
 Opens up ways for further
studies & illuminates human
behavior

Case Studies

Descriptive; An observation technique in which one
person is studied in depth in the hope of revealing
universal truths

Ex: studies on impairments after brain damage in
certain areas has led our knowledge of the brain
O
Advantage: very revealing, give direction for further
study, show what can happen
O
Disadvantage = gives detailed information about one
person & can’t be generalized to the larger population;
unrepresentative info can lead to false conclusions &
mistaken judgments

Dramatic stories & personal testimonies command out
attention BUT are usually atypical “well I have a cousin
that…”
Point to remember: CS give a glimpse & ideas for
future study but to find truths we must use other
research methods

Surveys
O
Descriptive Technique used to discover self reported
attitudes or behaviors of a particular group usually by
questioning a representative random sample of the group
O
Advantages
O
Looks at many cases in less depth, cheap, lots of
information fast from a large number of people
Asking questions = tricky & answers depend on way
questions are worded & respondents chosen
O

Disadvantage:

Wording effects: subtle changes can influence the
respondents answer/opinions


Q: Should cigarette ads and pornography be allowed
on television? (not allowed vs. forbid)
Can be biased answers:



People don’t give truthful answers
Give socially acceptable answers:
Unrepresentative sample
Population
O
Population: who you are
studying: the whole group you
want to study and from which your
samples will be drawn
O
O
Ex: women, men, Americans,
teenagers, elderly, preschool
children, Chinese, young adults,
teenagers in los Angeles
We must first decide who we want
to study, then take a representative
sample from that population under
investigation
O
B/C WE CANT STUDY EVERY
SINGLE INDIVIDUAL
Correlational Research
O Detects relationships between variables.
O Does NOT say that one variable causes
another.
There is a positive correlation
between ice cream and murder
rates. Does that mean that ice
cream causes murder?
Correlations
O
Correlation:
O
O

A measure of the extent to which two factors
vary together and thus how well either factor
predicts the other
An association
Correlation coefficient:



A statistical measure of the relationship
between the two things; (from -1 to +1)
Tells how closely two things vary together &
thus how one predicts the other
Ex: knowing how much aptitude test scores
correlate with schools success tells us how well
the scores predicts school success.
Scatterplots:
O
graphed cluster of dots, each of which
represents the values of the two variables; the
slope of the point suggests the direction of the
relationship between the two variables; the
amount of the scatter suggests the strength of
the relationship.
Positive & negative


positive correlation: means that as
one event increases, the second
event tends to increase; the two sets
of scores rise and fall together
◦ the more hours spent studying,
the higher/better the grade
◦ Height & weight
negative correlation: means that as
one event tends to increase, the
other event tends to decrease; two
scores relate inversely, as one rises
the other falls

◦
Toothbrushing & decay
the number of hours you spend
practicing shooting three
pointers, the less likely you will
be to miss them
Correlation
When one trait or behavior accompanies
another, we say the two correlate.
Indicates strength
of relationship
(0.00 to 1.00)
Correlation
coefficient
Correlation Coefficient is a
statistical measure of the
relationship between two variables.
r = + 0.37
Indicates direction
of relationship
(positive or negative)
Scatterplot
The Scatterplot below shows the relationship between height and
temperament in people. There is a moderate positive correlation of +0.63.
Scatterplot
The Scatterplot below shows the relationship
between height and temperament in people. There
is a moderate positive correlation of +0.63.
Correlation does and
not mean
causation!
Correlation
Causation
or
Illusory Correlations
O
O
O
O
O
O
O
Perceived but nonexistent
correlation
The perception of a relationship
where no relationship actually
exists. Parents conceive
children after adoption.
Ex: people conceive after
adoption
can you think of some?
Superstitions?
When believe there is a
relationships we tend to
notice and recall instances
that confirm our belief
Random coincidences = Just
random
Order in Random Events
O Given random data,
we look for order and
meaningful patterns.
O Given large numbers
of random outcomes,
a few are likely to
express order.
O Ex: Your chances of
being dealt either of
these hands is
precisely the same: 1
in 2,598,960.
Lab
Survey
Random Sampling
O
O
If each member of a population has an
equal chance of inclusion into a sample, it
is called a random sample (unbiased). If the
survey sample is biased, its results are not
valid.
For an accurate picture of a whole population’s
attitudes & experience we need a
representative sample…
O
O
O
Ex: a representative sample of students at your
school or American male shoe size
In order to generalize our results we
need a representative sample from the
population
Cant compensate for unrepresentative sample
by adding more people
O
w/o random sampling we would give
misleading results
With a representative sample Now we can
generalize our findings from the sample
experimented on to the population we are
attempting to study
The fastest way to know about the
marble color ratio is to blindly
transfer a few into a smaller jar and
count them.
Experimentation
Exploring Cause and Effect
O Like other sciences, experimentation is the
backbone of psychological research.
Experiments isolate causes and their effects.
O Experiments
O (1) manipulate factors that interest us, while
other factors are kept under
O (2) control.
O Effects generated by manipulated factors
isolate cause and effect relationships.
What is an experiment?
O Research method in which
an investigator
manipulates one or more
variables (independent
variable) to observe the
effect on a behavior or
mental process
(dependent variable)
O
variable: anything that can
vary– intelligence, TV
exposure, nutrition)
Steps of experimentation
1.
2.
3.
4.
5.
6.
7.
8.
Ask: a research question
Form a hypothesis
Identify the variables: independent & dependent
Choose participants
Randomly Assign participants: experimental &
control groups
Conduct the experiment: Manipulate the
Variables: independent & dependent
Measure effects of independent variable on
dependent variable
Analyze results with statistical procedures
Identify Variables
Independent
variable
O Experimental factor
that is manipulated;
the variable whose
effect is being
studied
O ex: drug dosage
O Ex: # hours slept
O Ex: amount of
coffee
Dependent
Variable
O Measureable behavior;
outcome factor; the
variable that will change
in response to the
manipulations of the
independent variable
Ex: Decreased
symptoms
O Ex: Test performance
O Ex: Performance on
reaction times
O
The variables
O Both variables are given precise operational
definitions, which specify the procedures
that manipulate the independent variable
O Ex: the amount of drug dosage
O Ex: the timing
O These definitions answer: “what do you mean
by that?”
O Ex” what do you mean by drugs taken”
Your turn…
Identify the IV & DV: Please match up as many scenarios as you can,
putting the DEPENDENT VARIABLE FIRST, and then describing
what affected it (the independent)
Ex. (DV) Increased weight loss was affected by (IV) hours you run
per week.










increased weight loss
The number of hours a person sleeps,
Taking vitamins,
increased energy and well being
Eating healthy foods and exercising,
Working with someone more fit,
test performance
Hours you run per week,
increased pace of your own workout
increased cardiovascular health
Confounding variables
O Other factors that can potentially influence
the results of the experiment
O Age, education, socioeconomic status,
weight, environment
O Random assignment controls for possible
confounding variables
Choosing participants:
Random Assignment
Participants from the population being studied are
randomly selected to participate
2. What is random selection
1.
O Participants are randomly assigned to one of two
groups: to experimental and control groups by chance,
minimizing preexisting differences between those
people assigned to the different groups
O Participants are blindly assigned to these groups,
meaning they are uninformed about what treatment (if
any) they are receiving
O This Allows researchers to hold constant all factors
except for the one they are manipulating
O Eliminates alternative explanations for findings
2 groups:
O Experimental group:
O the group that is exposed/receives to the
treatment (exposed to the IV)
O Control group/comparison group:
O group that is not exposed to the treatment
(IV); contrasts with the experimental group &
serves as a comparison for evaluating the
effect of the treatment
Placebo Effect
O To know how effective a
therapy is, researchers
must control for a
possible placebo effect
O Placebo:
O some intervention:
taking a pill, receiving
and injection, or
undergoing an
operation that
resembles medical
therapy but has no
medical effect.
O Placebo effect:
O A change/effect on
a participants
illness or behavior
that results from an
imagined
treatment rather
than to a
medical/actual
treatment
The effect…

Researchers believe that
placebos work by reducing
tension and distress and by
creating powerful self-fulfilling
prophecies so that individuals
think and behave as if the drug is
actually affective

35-75% of patients benefit from
taking placebos for a variety of
problems: pain, depression,
headaches

How can it be avoided for
research purposes?
Double blind experiment
O An experiment in which neither
the participants nor the
experimenters know which
group received the treatment
(which gets the drug and which
gets the placebo)
O Eliminates the possibility the
researcher will unconsciously
find what he/she expects about
the effects of the drug
O Allows researchers to check
actual effects of treatment
rather than participants belief
O
Ex: FDA
Single blind experiments
O Single Blind Experiment
O An experiment in
which the participants
are unaware of which
participants received
the treatment
O Participants are
“blind” in the sense
that they don’t know if
they get the drug or
placebo
 “blindly” assigned to
the Experimental group
or control group
Statistical Reasoning
Statistical procedures analyze and interpret data allowing us to see what the
unaided eye misses.
Once researchers have collected all their data, how are they supposed to
organize it so that it makes sense?
They need to figure out how they can organize it so that they can analyze it to
see whether their findings support or contradict their hypothesis.
Composition of ethnicity in urban locales
Statistics:
O Statistics: branch of
mathematics concerned
with summarizing and
making meaningful
inferences from
collections of data
O 2 types used in
psychology: descriptive
& inferential
O Often misread and thus
mislead the
public…doubt big
rounded numbers!!!
Descriptive statistics
O Descriptive Statistics:
listing and summarizing
of data such as using
graphs and averages
O Frequency distributions,
bell curves, central
tendency, variability,
correlation coefficients
Descriptive Statistics
Central tendency
O
Central tendency refers to how the data measure the
center of a set of data; the mean, median, and mode all
point to where the middle of the data should be
O
Mode: most frequently occurring score in a
distribution
O
Mean: arithmetic average of scores in a
distribution obtained by adding the scores and
then dividing by the number of scores that were
added together.
O
Is the most affected by extremes scores in the data
O
Median: midpoint; 50th percentile; The middle
score in a rank-ordered distribution.
O
Measures of central tendency neatly summarize
data
Measures of Central Tendency
A Skewed Distribution
What is skewed? If the mean, median, and mode are all the same number,
the graph of the data will look like a normal curve; if they are all different the
graph will be skewed or off center in some way
Positively skewed: occurs when scores pull the mean toward the higher end
of scores (the mean is more positive or greater than the rest of the scores)
Negatively skewed: occurs when scores pull the mean toward the lower end
of scores
Measures of Variation
MOV ask: How similar or diverse are scores?
Variation: how similar or diverse the scores in the data set are
O
Averages taken from scores with low variability are more reliable than averages taken
from scores with high variability
Range: The difference between the highest and lowest scores in a distribution.
Standard Deviation: A measure of how much scores vary around the mean score(
how close or far scores are from the mean); the higher the SD the less similar the
scores are; you want a smaller SD because you are able to draw more stable
conclusions from the data set
O Ex: university score of intelligence vs larger community college of more
diverse scores
O Scores most often form bell shaped curve= Normal curve
Standard Deviation
Normal curve
O
Normal curve:
symmetrical bell-shaped
curve that describes the
distribution of many types
of data (normal
distribution)
O
Most scores fall near the
mean
O Ex: 68% fall within
one standard deviation
of mean on either
side; fewer and fewer
at extremes
Illusion of Control
That chance events are subject to personal control is
an illusion of control fed by:
1.
Illusory Correlation: the perception of a
relationship where no relationship actually
exists.
2.
Regression Toward the Mean: the tendency
for extremes of unusual scores or events to
regress toward the average.
Inferential statistics
O
O
Inferential Statistics: method used
to determine whether research data
supports the hypothesis or whether
results are due to chance;
Making an Inference: A statistical
statement of how frequently an
obtained result occurred by
experimental manipulation or by
chance.
O
O
O
O
Use stats to make
generalizations about the
population based on the
findings of the study
Use statistical tests
Determine probability/chance
Determine statistical
significance
Reliability & Validity
O Reliability: the extent to which a test yields consistent
results; based on the consistency of scores on two
times or halves of the test(consistent scores)
O If the two scores agree or correlate then the test is
reliable
O Validity: the extent to which the test actually
measures or predicts what it says it is measuring
O Content validity: tests measures what they are
supposed to measure
O AP Psych exam should cover what we learned
O Predictive validity: a test should predict what it is
supposed to predict
O Ex: drivers test, SAT
Making Inferences: Reliability
When is an Observed Difference Reliable?
Representative samples are better than
biased samples.
1.
1.
Never extremes/never whole population
sampled
Less-variable observations are more
reliable than more variable ones.
More cases are better than fewer cases.
2.
3.
1.
2.
Averages should be based on many cases
Generalizations that are based on few
cases are UNRELIABLE
Statistical Significance
O When is a difference significant?
O When sample averages are reliable &
the difference between them is
relatively large, we say the difference
has statistical significance. It is
probably not due to chance variation.
O Means the observed difference is
probably not due to chance variation
between the samples
O Odds of occurring by chance are
less than 5%
O P score: indicates statistical
significance <.05, or .0001
Lab Experiements vs Reality
O Intended to be
simplified reality;
stimulates &
controls features of
everyday life
O Not recreating but
testing theoretical
principles
O Resulting principles
not specific
findings that help
explain behavior
O
O
O
O
O
O
Study them to learn how
different species think, learn &
behave; BUT also to learn about
people
Experiments have led to:
O insulin, vaccines,
transplants
Respect them for similarities,
protect them from suffering
Protestors: against completely,
only observations
Animals used for research only
1%
Issue: research has led to many
findings, treatments and cures
Ethical issues: animal testing
Ethical issue: People
O Ethical principles
O
O
O
O
developed by the
American
Psychological
Association 1992
1. informed
consent of
participants
2. protect from
harm & discomfort
3. confidentiality
4.debriefing
Ethical Issues in Psychology
O
O
O
O
O
In 1992 the American
Psychological Association
published a set of ethical
principles…
Informed consent of
potential participants
Must protect them from
harm & discomfort
Confidentiality
Deception & Debriefing:
must fully explain
experiment after
O Stanford Prison
Experiment
O Milgram Experiment
O The knowledge of
psychology…
O
To some it is common sense
to others they are concerned
it is becoming too powerful
O Yes it Can be used for good
or evil or to manipulate
people….BUT…
O Although it has power to
deceive its purpose is to
enlighten: enhance learning,
creativity, compassion, world
problems of war, family crises,
crime, prejudice= all which
involve attitudes & behaviors