a look at psychological research. general principles the concern for precise measurement operational...
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A look at psychological A look at psychological researchresearch
General principlesGeneral principles
The concern for precise measurementOperational definitions – definitions
which specify the procedure used to measure something
Also, a way to give a study’s focus of concern a numerical value
How do you measure anger, love, intelligence?
Fun way to start Anecdotes, stories
Research designsResearch designsNaturalistic observations
◦A careful examination ofan individual’s or animal’sbehavior in more or less natural conditions
No manipulation, just observationOften the first step in generating
hypothesis’
Case historiesCase historiesA thorough description of aperson or small group ofpeople with unusual or noteworthy qualities
Another source of hypothesis’
Just a super-sized anecdote?
surveyssurveysA study of the prevalence of
certain beliefs, behaviors, or attitudes based upon people’s responses to specific questions
Many problems: sampling nonchalance the questions bias
Sample Social SurveySample Social Survey
1. Are you involved in any kind of social activity?
a) yes
b) No
c) Somewhat
2. Do you agree that you are well informed about the happenings around you and also current affairs?
a) Strongly agree
b) Agree
c) Somewhat agree
d) Disagree
3. On an average how much do you spend daily in reading the newspaper or watching television?
a) More than one hour
b) Less than one hour
4. Do you interact with outsiders a lot?
a) yes
b) No
c) Sometimes
5. Have you ever taken part in any lawful public demonstration?
a) yes
b) No
6. Have you even been caught in any illegal activity?
a) Yes( Please provide details)
b) No
correlationscorrelationsA measure of the relationship between
two variables
Variable – a measurable item that can vary in magnitude
Correlational study – a procedure in which the investigator measures the relationship between two variables without controlling either one
CorrelationsCorrelationsexamplesexamplesBetween class attendance and final gradeBetween hours worked and $ earnedBetween smiles given and smiles received
Between miles run/week and 5k timeBetween hours on internet and final gradeBetween exercise sessions and weight
Between hair color and grade point average
Correlations graphicCorrelations graphicexamplesexamples
The correlation coefficientThe correlation coefficient
R = the mathematical relationship between two variables, ranging from -1 to 1
Positive correlations approach 1Negative correlations approach -1A R of 0 means that there is no
relationship between the two variablesLook to R’s absolute value when
assessing its strength
Illusory correlationsIllusory correlations
An apparent relationship based upon casual observations of unrelated or weakly related events
Do people really getwild under a full moon?Does the weather affectarthritis symptoms?
Correlations and causationCorrelations and causation
No matter how it might seem, correlations do not tell us about cause and effect
We never really know if changes in one variable affects the other, or
If a third, lurking, variable controls them both.
Correlations help us predict but not explain or control behavior or experience.
experimentsexperiments
Milgram Experiment
experimentsexperimentsA study in which the investigator
manipulates at least one variable while measuring at least one other variable
By adjusting one variable or factor, while keeping all other factors constant, we can determine if that factor causes changes in the other(s)
More definitions:More definitions:variablesvariablesIndependent variable – the
variable which is manipulated, or adjusted, by the investigator
Dependent variable – the variable which is measured by the investigator to determine the effects of the independent variable
groupsgroupsExperimental group – receives the
treatment (independent variable) that the experiment was designed to test
Control group – handled exactly the same as the experimental group except for the independent variable
Control groups usually receive a placebo
Hazards to be prepared forHazards to be prepared for
Biased groupsTo make sure that the experimental
and control groups are as similar as possible, before being introduced to the independent variable we use random assignment
Every participant must have an equal chance of being placed in either the experimental or the control group
more hazardsmore hazards
Even unconsciously, investigators want to see their hypothesis confirmed and unintentionally might distort the results
Placebo effectAlso, the experiment’s participants
might try to help prove the hypothesis
Solution – Double blind – a procedure in which both the observer and the participant are unaware of which participants received which treatment and the experiment’s goals
reviewreviewHypothesisSelect Method & Operational
DefinitionRandom Assignment of groupsRun experiment (double blind)Collect and analyze results (data)Peer reviewReplicationEthics