Difficulty: Introductory to Intermediate | Prerequisites: "What Is Social Psychology" notes
Social psychologists use the scientific method to test theories about social behaviour, drawing predictions (hypotheses) from theory and testing them empirically. Research broadly splits into experimental methods (which manipulate variables to find causes) and non-experimental methods (surveys, archival research, case studies) which identify patterns but cannot prove causation. Good research design controls for confounding variables, maintains internal validity, and follows strict ethical principles.
Scientific method
A systematic approach to acquiring knowledge in which research predictions are derived from theory and tested against observable data. In simple terms, you start with a theory, form a testable prediction, collect data, and see whether the prediction holds.
Scientific hypothesis
A prediction about causes or about relationships between variables that can be empirically tested. Karl Popper defined it as a statement that can be disproved but not proved. Think of it as a claim specific enough that evidence could show it wrong.
Falsifiability (Popper)
The principle that a scientific hypothesis must be stated in a way that allows it to be disproved. If no conceivable evidence could contradict it, it is not scientific.
Replication
Repeating a study to see whether the same results emerge. It matters because it allows the scientific community to produce repeated evidence and guards against findings that are tied to one particular set of testing circumstances.
Independent variable (IV)
The variable the researcher manipulates or that changes of its own accord. It is the presumed cause. In simple terms, it is the thing the experimenter changes to see what happens.
Dependent variable (DV)
The variable that changes as a consequence of changes in the independent variable. It is the measured outcome. Think of it as the result you are watching for.
Confounding variable
An unintended independent variable that covaries with the intended independent variable. It muddies the results because you cannot tell whether the IV or the confound caused the change in the DV.
Random allocation
Assigning participants to experimental conditions by chance. This reduces the influence of confounding variables by spreading individual differences evenly across conditions.
Internal validity
The degree to which an experiment actually demonstrates a causal relationship between the IV and the DV, free from confounds. Laboratory experiments should always be high on internal validity.
External validity
The degree to which findings from a study can be generalised to other settings, populations, and times. Field experiments tend to be stronger on this than lab experiments.
Demand characteristics
Cues in an experiment that suggest to participants how they are expected to behave. Along with evaluation apprehension and social desirability, these are responses by participants that can bias results.
Double-blind procedure
An experimental setup in which neither the participant nor the experimenter knows which condition the participant is in. This reduces experimenter bias.
Experimental manipulation
The deliberate alteration of the independent variable by the researcher. It is necessary to determine a relationship between variables.
Non-experimental methods
Research approaches that do not involve manipulating an independent variable. These include archival research, surveys, and case studies.
Field experiment
An experiment conducted in a natural, real-world setting rather than a laboratory. It trades some internal validity for greater external validity.
Discourse analysis
A form of qualitative analysis on textual information. It examines how language is used in social contexts rather than counting numerical data.
t test
A statistical test commonly used in psychological research to determine the significance of a difference between the means of two groups of scores.
Quantitative data
Numerical data analysed with statistical methods. Most mainstream social psychological knowledge is derived from the statistical analysis of quantitative data.
Using the scientific method means that research predictions are derived from theory, not from intuition alone
A crucial aspect of the method is that it tests a theory by how it corresponds with fact
Social psychologists are scientifically innovative when they construct a theory based on background knowledge, experience, or observation
The choice of investigative method is determined by the nature of the hypothesis, the resources available, and the ethics of the method. It is not determined by the gender of participants
Research in social psychology broadly uses two types of methods: experimental and non-experimental
In an experiment, the researcher manipulates the independent variable and measures its effect on the dependent variable
A one-factor experimental design can be based on two levels of one independent variable (e.g. treatment vs. control)
To avoid confounding results, all conditions must be identical except for the independent variable of interest
Laboratory experiments are designed to control for confounding variables and should always be high on internal validity
The double-blind procedure reduces experimenter bias by keeping both the participant and the experimenter unaware of condition assignment
Confounding variables: Unintended variables that covary with the IV. Random allocation of participants to conditions is one way to reduce them
Demand characteristics: Cues that tell participants what the experimenter expects. Together with evaluation apprehension and social desirability, these are participant responses that can bias results
Experimenter bias: Systematic error introduced by the researcher's expectations. Addressed by double-blind procedures
Include archival research, surveys, and case studies
Field experiments sit between lab experiments and non-experimental methods: they manipulate a variable in a natural setting (e.g. Rebecca's staring study at traffic lights)
Non-experimental methods cannot establish causation but are useful for studying phenomena that would be unethical or impractical to manipulate
Most mainstream social psychological knowledge comes from the statistical analysis of quantitative data
t tests are commonly used to determine the significance of a difference between the means of two group scores
Discourse analysis is a qualitative method that analyses textual information rather than numerical data
"The scientific method requires a laboratory." It does not. The scientific method is about deriving predictions from theory and testing them empirically. This can happen in a lab, a field setting, or through archival data
"If an experiment has high internal validity, it must also have high external validity." These often trade off against each other. Lab experiments maximise internal validity (control over confounds) but may lack external validity (generalisability to real life). Field experiments tend toward the reverse
"A t test proves a hypothesis." A t test determines the statistical significance of a difference between group means. It does not prove anything; it tells you how likely it is that the difference occurred by chance
"Replication just means doing the same study again to be thorough." Replication serves a specific scientific purpose: it allows the community to produce repeated evidence and guards against findings that are artefacts of a particular testing situation
True or false: Random allocation eliminates confounding variables entirely. False – it reduces them but does not guarantee their elimination
Fill in the blank: The variable the researcher manipulates is called the _______ variable. Independent
True or false: A field experiment is a type of non-experimental method. False – it is experimental because a variable is manipulated, but it takes place in a natural setting
Fill in the blank: Karl Popper argued that a scientific hypothesis must be capable of being _______. Disproved (falsified)
True or false: Discourse analysis is a quantitative method. False – it is a qualitative method applied to textual information
Q: What does the use of the scientific method in social psychology imply?
A: That research predictions are derived from theory. The method requires forming testable hypotheses and checking them against empirical evidence.
Q: In an experiment on the effects of visual feedback, half the participants see a videotape of their facial reactions when meeting a stranger and half do not. What is the independent variable?
A: Visual feedback (whether or not participants see the videotape).
Q: What is the purpose of random allocation in experiments?
A: To reduce confounding variables by distributing individual differences evenly across experimental conditions.
Q: Why are laboratory experiments designed the way they are?
A: To control for confounding variables. By holding all conditions identical except for the independent variable, the researcher can be more confident that any observed effect is caused by the IV.
Q: What distinguishes experimental from non-experimental methods?
A: Experimental methods involve manipulating an independent variable and measuring its effect on a dependent variable. Non-experimental methods (surveys, archival research, case studies) observe and record without manipulation.
Q: What is a confounding variable?
A: An unintended independent variable that covaries with the intended independent variable, making it impossible to determine which variable caused the observed effect.
Q: What do evaluation apprehension, demand characteristics, and social desirability have in common?
A: They are all responses by participants that can bias an experimental result.
Research methods underpin every other topic in social psychology. When you study attitudes (Ch. 5-6), group processes (Ch. 8-9), or prejudice (Ch. 10-11), you will encounter experiments that use the exact designs described here: independent and dependent variables, random allocation, and controls for confounds.
The ethics material in this chapter connects forward to Milgram's obedience studies (Ch. 7), one of the most debated cases in research ethics.
Research methods social psychology, scientific method psychology, independent variable, dependent variable, confounding variable, internal validity, external validity, demand characteristics, double-blind procedure, field experiment, laboratory experiment, random allocation, replication psychology, falsifiability Popper, t test psychology, discourse analysis, quantitative data, Vaughan social psychology 8e Chapter 1