Research Methods
Psychology Research Methods Terms: Variables, Sampling & Ethics
Research methods language shows up in almost every psychology course, on almost every kind of assessment, because it is the language used to describe every study you will ever read.
Learn to label the pieces of a study — what was manipulated, what was measured, who was assigned where — and most research questions become straightforward.
Study tip
If you can name the independent variable, the dependent variable, and the control group in any study description, you can answer most research-methods questions you meet.
12 terms, defined
Hypothesis
A testable, falsifiable prediction about the relationship between two variables.
Example: 'Students who sleep 8 hours score higher on a memory test than students who sleep 4 hours.'
Independent variable
The variable the researcher deliberately manipulates to see what effect it has.
Example: The amount of sleep participants are assigned to get.
Dependent variable
The outcome the researcher measures — it depends on the independent variable.
Example: The number of words recalled on the memory test.
Operational definition
A precise statement of how a variable is measured or manipulated in a specific study.
Example: Defining 'stress' as a score above 20 on the Perceived Stress Scale, not just 'feeling overwhelmed.'
Random assignment
Placing participants into experimental groups by chance so pre-existing differences spread out evenly.
Example: Drawing names to decide who gets the 8-hour and who gets the 4-hour sleep condition.
Random sample
A sample in which every member of the population has an equal chance of being selected, making results generalizable.
Example: Pulling 200 student ID numbers at random from the full enrollment list.
Confounding variable
An uncontrolled third factor that could explain the results instead of the independent variable.
Example: If the 8-hour sleep group also happened to be the honors class, ability is confounded with sleep.
Placebo effect
Improvement caused by a participant's expectations rather than the treatment itself.
Example: Feeling more alert after a sugar pill you were told was caffeine.
Double-blind procedure
A design in which neither participants nor the researchers interacting with them know who is in which condition.
Example: A drug trial where the nurse handing out pills doesn't know which are active.
Correlation coefficient
A number from -1.00 to +1.00 describing the strength and direction of a relationship between two variables. It never proves causation.
Example: Ice cream sales and drowning deaths correlate at about +.70 — because both rise with summer heat.
Informed consent
Participants must be told enough about a study to freely decide whether to take part.
Example: Signing a form describing the tasks, time commitment, and right to withdraw at any point.
Debriefing
Fully explaining a study's true purpose, including any deception, after participation ends.
Example: Telling participants the 'other student' who criticized them was actually a confederate.
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Take any study you've read and name its IV, DV, and one confound.
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Unit 1
Biological Bases
22 terms with examples
Unit 2
Cognition
20 terms with examples
Unit 3
Development & Learning
22 terms with examples
Unit 4
Social & Personality
20 terms with examples
Unit 5
Mental & Physical Health
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Foundations
Perspectives & Foundations
9 terms with examples
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