Glossary
Case Study
A descriptive research method in which one individual or group is studied in depth in the hope of revealing universal principles.
Example:
The detailed investigation of a rare neurological condition in a single patient would be an example of a case study.
Confounding Variable
A factor other than the independent variable that might produce an effect in an experiment, making it difficult to determine the true cause of the results.
Example:
If a study on exercise and mood doesn't account for participants' diet, diet could be a confounding variable influencing their mood.
Control Group
In an experiment, the group that does not receive the treatment or receives a placebo, serving as a comparison for evaluating the effect of the treatment.
Example:
In a drug trial, the control group might receive a sugar pill instead of the actual medication to account for the placebo effect.
Correlational Study
A research method that examines the extent to which two variables are related, allowing for prediction but not cause-and-effect conclusions.
Example:
A correlational study might find that students who spend more time studying tend to have higher grades, but it doesn't prove studying causes higher grades.
Dependent Variable (DV)
In an experiment, the factor that is measured; it may change in response to manipulations of the independent variable.
Example:
If a study examines how different teaching methods affect student test scores, the dependent variable would be the test scores.
Double-Blind Procedure
An experimental procedure in which both the research participants and the research staff are ignorant (blind) about whether the research participants have received the treatment or a placebo.
Example:
In a drug trial, using a double-blind procedure prevents both the patients' and doctors' expectations from influencing the results.
Ethical Guidelines
A set of principles and rules that researchers must follow to ensure the well-being, dignity, and rights of participants in psychological studies.
Example:
Obtaining informed consent and ensuring confidentiality are crucial ethical guidelines that protect research participants.
Experiment
A research method where an investigator manipulates one or more factors (independent variables) to observe the effect on some behavior or mental process (dependent variable), allowing for cause-and-effect conclusions.
Example:
To test if caffeine improves memory, a researcher might conduct an experiment where one group drinks caffeinated coffee and another drinks decaf, then compare their test scores.
Experimental Group
In an experiment, the group that receives the treatment or the manipulated independent variable.
Example:
If a new study technique is being tested, the experimental group would be the students who are taught using that new technique.
Hypothesis
A testable prediction, often implied by a theory, that specifies a relationship between variables.
Example:
A hypothesis might state: 'Students who get more sleep will perform better on their exams.'
Independent Variable (IV)
In an experiment, the factor that is manipulated by the researcher; its effect is being studied.
Example:
In an experiment testing the effect of sleep on test performance, the amount of sleep (e.g., 4 hours vs. 8 hours) would be the independent variable.
Naturalistic Observation
A research method involving observing and recording behavior in naturally occurring situations without trying to manipulate or control the situation.
Example:
A psychologist studying social interactions might use naturalistic observation by watching children play on a playground without interfering.
Operational Definition
A carefully worded statement of the exact procedures (operations) used in a research study to define research variables, allowing for replication.
Example:
An operational definition of 'happiness' in a study might be the score a participant receives on a specific happiness questionnaire.
Placebo Effect
Experimental results caused by expectations alone; any effect on behavior caused by the administration of an inert substance or condition, which the recipient assumes is an active agent.
Example:
A patient feeling less pain after taking a sugar pill, simply because they believe it's a painkiller, is an example of the placebo effect.
Population
In research, the entire group of individuals from which a sample is drawn and to whom the conclusions of the study are intended to apply.
Example:
If a researcher wants to study the reading habits of teenagers in the U.S., all U.S. teenagers would be the population.
Random Assignment
Assigning participants to experimental and control groups by chance, minimizing pre-existing differences between the groups and ensuring groups are comparable.
Example:
To ensure fairness, researchers use random assignment to decide whether a participant goes into the group receiving the new drug or the placebo group.
Random Sampling
A method of selecting a sample from a population in which each member of the population has an equal chance of being included, ensuring representativeness.
Example:
To get a truly representative opinion on school lunches, a school might use random sampling by drawing student names from a hat.
Replication
Repeating the essence of a research study, usually with different participants in different situations, to see whether the basic finding extends to other participants and circumstances.
Example:
If a study finds that a new teaching method improves grades, other researchers might attempt replication in different schools to confirm the findings.
Research Methods
Systematic approaches used by psychologists to investigate behavior and mental processes, forming the foundation of scientific knowledge in the field.
Example:
Understanding different research methods helps psychologists determine if a new therapy is truly effective or if two behaviors are simply related.
Sample
A subset of the population selected for study, ideally representative of the larger group to allow for generalization of findings.
Example:
From the entire population of U.S. teenagers, a researcher might select a sample of 1,000 teenagers to participate in their study.
Survey
A research method where self-reported attitudes or behaviors of a particular group are gathered by questioning a representative, random sample of the group.
Example:
A political scientist might use a survey to gauge public opinion on a new policy by asking a large, diverse group of voters.
Theory
An explanation using an integrated set of principles that organizes observations and predicts behaviors or events.
Example:
Freud's psychoanalytic theory attempts to explain personality, motivation, and mental disorders by focusing on unconscious drives.