Research Methods Lecture Notes

Social Psychology in Action (within psychological tradition)

Research into social psychological phenomena is necessary, since what we as lay social psychologists think is true of social behavior is not always true

Think of some well-known adages (such as "opposites attract" or "birds of a feather flock together"). Which of these statements is true? Our common, everyday beliefs are sometimes very contradictory.

How Do Social Psychologists Study Influence, Perception, Interaction?

Develop Theories

Provides a general explanation for social behavior

Statement about constructs- abstract concepts

Describes causal relationships

General in scope; intended to apply to (generalize to) many types of people, times, settings

Conduct Experiments

Develop testable hypotheses (based on theory)

Manipulate independent variables and study effects on dependent variables

Independent variable - the var. that is manipulated

Dependent variable - the var. that is measured

Examples

Problems Encountered (some of them anyway)

(Note: study research section of Chapter I; go to web links for this section)

Construct Validity (generally-speaking)

The extent to which the independent and dependent variables really do correspond to the theoretical constructs that you're trying to operationalize

Threats to construct validity (generally-speaking)

-not measuring the right construct

-demand characteristics

-social desirability response bias

-manipulations influencing more than one construct

Specific Kinds of Validity and Threats to "Experiments"

Internal validity (one specific kind of construct validity)

The extent to which a researcher can conclude that a change in the dependent var. has really and truly been caused by a change in the independent var.

Threats to internal validity

using nonexperimental design (where independent and dependent var. are both being measured; nothing is actually manipulated)

Experimenter expectancy effects

Demand characteristics

So, what do you do to ensure internal validity?

Use an experimental design in which

a) independent var. is manipulated

b) random assignment is employed

And what else? You tell me in your own words:

External validity

How generalizable results are to other appropriate people, times, & settings

Threats to external validity

• participants representative of population?

• representative vs. convenience samples?

(e.g., culture, SES)

• is the lab setting comparable to real life?

mundane versus experimental realism

So, what do you do to ensure external validity?

You tell me in your own words:

Practicing Internal and External Validity

Here is a study regarding sentence lengths in criminal proceedings. Think about this study and determine its pros and cons it in terms of internal and external validity.

Hypothesis: "Defendant attractiveness causes sentence lengths"

--> 10 observers (O's) attend various court proceedings all over the state of Pennsylvania

--> O's rate 74 defendants on nine scales (one of which is "attractiveness")

--> O's later found out sentence length later from court records

Finding: Correlation between sentence length and attractiveness = -.40

Write down in your own words:

Was hypothesis confirmed?

Do you think they've shown that defendant attractiveness causes sentence lengths?

What pros and cons you see with internal and external validity:

Pros Internal Validity:

Cons Internal Validity:

Pros External Validity:

Cons External Validity:

Internal Validity

Pros:

Rated many different characteristics (demand & expectancy)

Cons:

nonexperimental (Ç causality)

External Validity

Pros:

74 different defendants (representative sample)

Various different crimes (representative sample)

Different regions (counties)

Different observers

Real-world

Alternative explanations?

•Money --> attractiveness (haircut, suit, plastic surgery)

•Race (race differences between O's and defendants)

•Seriousness of crimes committed (oh, he just picked her pocket, vs. he murdered his wife)

How could you improve this study? Write down your improvements here:

Ethics of Experiments

Deception

Use of confederates

IRB

Institutional Review Board: panel of individuals decide whether a proposed experiment is ethical

Informed consent

protecting subjects from harm

right to withdraw at any time

Debriefing

answer participants' questions

explain necessity for deception

discuss purpose of study

opportunity for researcher to detect any possible negative, lasting effects of experiment