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