Transcript Psychology as a Science - Immaculateheartacademy.org

Psychology as a Science
Research Methods
The Need for Psychological Science
• Common Sense?
• “Hindsight is 20:20”
– Hindsight Bias
• Question everything!
– Critical Thinking:
The Scientific Method
• Definition: Approach used by psychologists to
systematically acquire knowledge and
understanding about behavior and other
phenomena
• Steps:
1. Identify Problem or Question
2. Formulate a Hypothesis
3. Collect Data
4. Analyze Data
5. Draw Conclusions
Theories v. Hypotheses
Theory
Hypothesis
• Definition: broad explanations • Definition: a prediction,
and predictions concerning
stemming from a theory,
phenomena of interest
stated as a testable question
– Based on observation and
• Example:
predicts future
“People with high self-esteem
behaviors/events
are more likely to express a
• Example:
secure attachment style in
Attachment Theory in adult
relationships than those with
relationships:
low self-esteem.”
--Four attachment styles have
been identified in adults:
secure, anxious-preoccupied,
dismissive-avoidant, and
fearful-avoidant.
PSEUDOSCIENCE
• Pseudoscience
– diverges from the required standards for work or is
unsupported by sufficient scientific research
• Examples:
– Phrenology (bumps on head)
– Astrology
– Telepathy
– UFOs
Research Terms
• Study: broad term used to describe a specific
group of research (includes prior research,
hypotheses, participants, etc.)
• Participants: people chosen to partake in a study
(representative sample) a.k.a. subjects
– Population: a whole group of people based on a
common characteristic
– Sample: a small representation of a particular
population
• Random Sample: fairly represents a population;
every member of a population has an equal
chance to partake in the study
Research Terms cont’d
• Variables: Behaviors, events, or other
characteristics that can change in some
way.
Research Methods
• Archival Research: use existing data to test a
hypothesis (e.g.: newspapers, census
documents, college records).
• Naturalistic Observation: investigator observes
a naturally occurring behavior and does not
make a change in the situation
• Survey Research: using a sample of a
population, people are asked a series of
questions about their behavior, thoughts, or
attitudes.
• Case Study: an in-depth, intensive investigation
of an individual or small group of people
• Correlational Research: shows the
relationship between two sets of
variables to determine if they are
associated or “correlated”
• Example: Violent TV and Viewer Aggression
– Positive Correlation: as 1 variable increases,
the other variable increases
– Negative Correlation: as 1 variable
increases, the other variable decreases
• Correlation does NOT EQUAL Causation!!!
Violent TV and Aggression
Level of Agression
Positive Correlation
100
90
80
70
60
50
40
30
20
10
0
<1 hr
1-3 hrs
3+ hrs
Hours of Violent TV
What does this mean??
Hours of exercise & Weight
Pounds
Negative Correlation
240
220
200
180
160
140
120
100
< 3 hrs
3-5 hrs
5+ hrs
Hours of excercise per week
What does this mean??
Correlation ≠ Causation!
• Illusory correlation: perception of a
relationship where none exists
– 3rd variable that has an influence
• a.k.a. extraneous variable
– Length of Marriage & Hair Loss
• 3rd variable: age
Experimental Research
• Investigation of the relationship between
two or more variables by deliberately
producing a change in one variable in a
situation and observing the effects of
that change on other aspects of the
situation
• The ONLY way to demonstrate causation!
Key Terms in Experimental Research
• Manipulation: the change that the
experimenter deliberately produces in a
situation
• Experimental Group: The group receiving the
manipulation
• Control Group: The group that receives no
manipulation, i.e. “stay normal”
• Independent Variable: variable that is
manipulated (effect is studied)
• Dependent Variable: variable that is measured
and is expected to change due to the
manipulation (i.e. the IV changes the DV)
• Random Assignment: participants are assigned
to different experimental groups based on
chance
• Significant Outcome: meaningful results make it
possible to support hypothesis
• Replication: repetition of research, sometimes
changing procedures, settings, or participants in
order to strengthen confidence in previous
findings
• Double-Blind Procedure: an experimental
procedure in which both the experimenter (s)
and participants do not know which group was
the control and which was treated
Ethics
• APA Guidelines
– Protection of participants from physical and
mental harm
– Rights of participants to privacy regarding
their behavior
– Assurance that participation in research is
completely voluntary
– Necessity of informing participants about the
nature of the procedures prior to their
participation in the experiment
• Informed Consent: document signed by
participants affirming that they know the
basic outline of the research study and
are aware of what their participation
involves.
• Debriefing: a conversation or document
reviewed by the participant with the
researcher explaining details about the
research, answering any questions, and
explaining any manipulation
Stanley Milgram
• 1960’s obedience study
• Participants were told to give increasingly
stronger electrical shocks to another person as
they answered each question incorrectly. The
highest level of shock could kill the person
– Reality: no actual shock was delivered but the
confederate was an actor who pretended to be
shocked.
• 65% of the participants delivered the highest
level of electrical shock when told to do so
• Why is this so important? Was this unethical?
– Extremely trying set of circumstances that could
have harmed the participants emotional/physical
state
Threats to Experiments
• Experimental Bias: factors that distort
how the independent variable affects the
dependent variable in an experiment
– E.g. Gender, Culture, Experimenter bias
• Placebo: a false treatment, such as a
pill, having no significant effect on
participant
Describing Data
• Mode: most frequently occurring score
• Mean: arithmetic average of a distribution
• Median: the middle score in a distribution
(half of the scores are above, half are
below)
• Outlier: scores that are so high or so low
that don’t fit into the central tendency
– *Can skew data results
FAQ’s about Psych. Research
• Can Lab experiments transfer to everyday life?
• Does behavior depend on one’s culture?
– Culture: enduring behaviors, ideas, attitudes, and
traditions shared by a large group of people and
transmitted from one generation to the next.
• Does behavior vary with gender?
– More similar than we are different yet we focus on
differences
• Why study animals? Is it ethical?
– Similar processes of learning, feeling, and exhibiting
emotion
– Naturalistic Observation over experimental to
protect the animals
?