Exam 2: Experimental Research Flashcards
Experimental research
A type of research where the investigator manipulates one or more independent variables and observes their effect on a dependent variable.
Nonexperimental research
Research that does not involve manipulation of variables but rather involves observing and measuring variables as they naturally occur.
Independent variable
The variable that is manipulated by the researcher in an experiment to examine its effect on the dependent variable.
Dependent variable
The variable that is measured to see if it is affected by changes in the independent variable.
Extraneous variables
Variables other than the independent variable that could influence the dependent variable if not controlled.
Confounding variable
An extraneous variable that systematically varies with the independent variable and could provide an alternative explanation for the results.
Conditions
Different levels or variations of the independent variable that participants in an experiment are exposed to.
Control
Procedures or techniques used to eliminate or reduce the impact of extraneous variables.
Manipulation
The process of systematically changing or altering the independent variable to examine its effects on the dependent variable.
Single factor two-level design
An experimental design involving one independent variable with exactly two levels or conditions.
Single factor multilevel design
An experimental design involving one independent variable with more than two levels or conditions.
Treatment condition
The condition in which participants are exposed to the experimental treatment or manipulation.
Control condition
The condition in which participants do not receive the experimental treatment, serving as a baseline for comparison.
Randomized clinical trial (RCT)
A study in which participants are randomly assigned to treatment or control groups to test the effectiveness of an intervention.
No-treatment control condition
A condition in which participants do not receive the treatment or intervention, allowing for comparison with those who do.
Placebo control condition
A condition in which participants receive a placebo treatment (inactive substance) to control for the effects of expectations.
Wait-list control condition
A control condition in which participants are placed on a waitlist to receive the intervention after the experimental group has completed it.
Placebo effect
A change in behavior or symptoms due to participants’ expectations of treatment rather than the treatment itself.
Placebo
An inactive substance or treatment given to participants to control for the placebo effect.
Between-subjects experiments
Experiments in which different participants are assigned to different conditions, so each participant experiences only one condition.
Random assignment
A method of assigning participants to different conditions randomly to ensure that each participant has an equal chance of being assigned to any condition.
Within-subjects experiments
Experiments in which the same participants experience all conditions, allowing for direct comparisons within each participant.
Carryover effect
When the effects of one condition persist and influence responses to subsequent conditions in a within-subjects design.
Practice effect
When participants’ performance improves over time as they practice or become familiar with the experimental tasks.
Fatigue effect
When participants’ performance declines over time due to tiredness or boredom.
Context effect (or contrast effect)
When participants’ responses in one condition are influenced by the context or contrast of previous conditions.
Counterbalancing
A technique used to control for order effects in within-subjects designs by varying the order of conditions across participants.
Internal validity
The extent to which an experiment accurately establishes a causal relationship between the independent and dependent variables.
External validity
The extent to which the results of a study can be generalized to other situations, people, or contexts.
Construct validity
The extent to which a test or experiment accurately measures the theoretical construct it is intended to measure.
Statistical validity
The extent to which statistical conclusions drawn from a study are accurate and reliable.
Experimenter expectancy effect
When the researcher’s expectations unintentionally influence participants’ behavior or the outcomes of the study.
Double-blind study
A study in which neither the participants nor the experimenters know which participants are receiving the treatment, controlling for bias.
