Controls and Subject Design - 5

Vocabulary flashcards reviewing experimental variables, subject designs, validity types, and confounding threats based on the lecture material.

Internal Validity

The extent to which changes in the dependent variable are directly due to the manipulation of the independent variable, achieved by controlling variables and addressing or removing confounds.

Independent Variable (IV)

The variable in an experiment that is manipulated by the researcher, consisting of different levels or conditions.

Dependent Variable (DV)

The measured outcome variable in an experiment that is evaluated to observe changes caused by manipulating the independent variable.

Confounding Variable

A variable that influences both the independent variable and dependent variable, creating alternative explanations for experimental results.

Control Variable

Any variable that an experimenter intentionally holds constant across all experimental groups.

Covariance

The joint variability between variables demonstrated when changing the independent variable leads to a corresponding change in the dependent variable.

Temporal Precedence

A prerequisite for establishing causality stating that the cause variable (independent variable) must precede the effect variable (dependent variable) in time.

Design Confound

A threat to internal validity that occurs when an experimenter fails to properly design the independent variable, introducing alternative explanations.

Selection Effect

A threat to internal validity in an experiment where participants in one level of the independent variable are systematically different from participants in another level.

Matched Groups

A technique used to prevent selection effects, especially in small samples, by matching participants on a specific variable (such as age, IQ, GPA, or gender) before assigning them to conditions.

Between-Subjects Design

An experimental design (also known as independent-groups design) where different groups of participants experience different levels of the independent variable.

Within-Groups Design

An experimental design (also known as paired-subjects design) in which each individual participant experiences all conditions or levels of the independent variable.

Mixed Design

An experimental design that incorporates both between-groups and within-groups variables.

Repeated-Measures Design

A type of within-groups design in which participants are measured on the dependent variable multiple times after exposure to each level of the independent variable.

Concurrent-Measures Design

A type of within-groups design where participants are exposed to all levels of the independent variable at roughly the same time, and a single preference is recorded as the dependent variable.

Posttest-Only Design

An independent-groups design in which participants are randomly assigned to independent variable levels and tested on the dependent variable only once after treatment.

Pretest/Posttest Design

An experimental design in which participants are randomly assigned to groups and measured on the dependent variable both before and after exposure to the independent variable.

Demand Effects

A disadvantage of within-subject designs where participants change their behavior because they deduce the experimenter's intentions.

Order Effects

A threat to internal validity in within-groups designs where the sequence in which conditions are presented impacts the dependent variable outcome.

Carryover Effect

A specific order effect where performance or responses in one condition are contaminated by lingering exposure from a previous condition.

Practice Effect

An order effect where participants either improve at a task due to repeated exposure or perform worse due to fatigue (fatigue effect).

Counterbalancing

The technique of presenting levels of the independent variable to participants in different orders to prevent or neutralize order effects in within-groups designs.

Full Counterbalancing

A method of counterbalancing in which all possible condition orders are presented to participants.

Partial Counterbalancing

A counterbalancing method in which only a subset of all possible condition orders is presented across participants, such as using a Latin square.

Construct Validity

The extent to which the variables in a study are effectively operationalized, measured, and manipulated.

External Validity

The extent to which the causal findings of a study generalize to other people or non-experimental situations.

Statistical Validity

The extent to which statistical conclusions are precise, accurate, account for effect size and confidence intervals, and have been replicated.