Science
Research Methods
Learning Objectives
You will learn how psychological research is conducted
You will learn about ethics in research
You will learn the strengths and weaknesses of different research methods
Scientific Method
Theories and hypotheses
Theories come from lots of data
A hypothesis is a testable prediction based on a theory
Theory: Fear is learned
Hypothesis: Repeated pairings of a loud noise and a white rat will result in a fear response when the rat is presented alone
Generate a hypothesis to test this theory
Theory: Dysfunctional thoughts lead to dysfunctional behavior
Hypothesis:??????
How we collect data
Naturalistic observation
Sort of like spying
No interference
Provides qualitative and quantitative descriptions
Relationship between hand-raising and grade in class?
Demographics of a population
Can’t draw causal inferences
How we collect data
Ethnography, or participant observer
Qualitative descriptions
Individual participates in a culture or group
Can’t draw causal inferences
Case Studies
Interviews, clinical examples, usually one or two people
Qualitative- cannot draw causal inferences
Survey Research- Self Report
Small sample represents a population
How we collect data
Psychophysiological data
Skin conductance
Blood pressure
Heart rate
Electroencephalogram (EEG)- electrical activity in the brain
Computerized axial tomography (CAT) scan- structure of brain
Functional magnetic resonance imaging (fMRI)- 3D image of brain and active areas
Validity
External
Can we generalize outside of our sample?
Are measures of anxiety similar to other measures
Internal
Are we measuring the thing we think we are measuring?
Do all these questions relate to anxiety?
Discriminant
Are our measurements inconsistent with measures of different things?
Is our measure of anxiety different from measures of depression
Reliability
Reliability-
Does it always measure the same thing?
Test-Retest Reliability
Is this measure consistent over time? Is it supposed to be?
Two major types of research
Correlational Research
Examines relationships between factors (-1 to +1)
Ask only if the relationship exists
CORRELATION DOES NOT INDICATE CAUSATION
Experimental
Situations controlled carefully
Uncovers causal relationships by isolating variables
Correlations
Correlations
Used in psychometrics- evaluating psychological measures
Validity and Reliability are evaluated with correlations
Correlations
Useful in telling us how to do an experiment, especially when the correlation is surprising
Experiments
Experiments
Involve two or more controlled conditions, comparing the outcomes
Control /comparison group- default, not exposed to variable being studied
Experimental/ criterion group- control + new variable
Different outcome = New Variable is responsible
Variables
Independent (IV)- manipulated
Dependent (DV)- measured, how you know stuff happened
Random Assignment
To make sure experimental and control groups are the same before the experiment, participants are randomly assigned to groups
Balances out individual differences
Can you think of a situation in which random assignment wouldn’t work?
Lets make an experiment
Question: We’ve noticed a correlation in children between eating vegetables and test scores (.75 )
Hypothesis?
IV (what’s manipulated):?
DV (what’s measured):?
Control Group:?
Experimental Group;?
HEY THIS MIGHT BE A GOOD QUIZ QUESTION
The Where and How
Field Study
Less controlled
More representative
Laboratory study
More controlled
Less representative
The where and how
Longitudinal Studies- take place over a long period of time, repeated measures
Everyone starts at the same point
Cross-sectional- faster than longitudinal, compares across age groups
Everyone tested at present, but categorized by age
Sequential- Combo of the two, participants start at different ages, followed over time
You try Identifying
A study that follows students from 1st to 12th grade?
A study started in 2005 that follows Vietnam, Iraq and Afghanistan veterans over 20 years.
A study that asks freshman, sophomores, juniors, and seniors about voting behavior?
A study that follows 2016 graduates for 10 years
Ethics
Protect participants from physical and psychological harm
Obtain informed consent from participants before their involvement in the study
Deception must be justified and cause no harm
Participant’s information must be kept private