Psychology of Learning

Module 02: Research Methods

Key Terms

2 × 8 Factorial Design: A factorial design with two independent variables, one having two levels and the other having eight levels; the notation indicates the number of levels of each IV.

A Priori Method: A way of fixing belief through pure reasoning, independent of empirical experience; conclusions depend on the quality of premises.

Between-Subjects Factor: An independent variable for which different participants are assigned to each level; also called independent groups factor.

Causal Inference: The determination that changes in one variable cause changes in another variable, the ultimate goal of experimental research.

Classical Conditioning: A learning process in which a neutral stimulus comes to elicit a response after being paired with an unconditioned stimulus.

Conditioned Response: In classical conditioning, the learned response elicited by the conditioned stimulus.

Conditioned Stimulus: In classical conditioning, a previously neutral stimulus that comes to elicit a response after being paired with an unconditioned stimulus.

Confounding Variable: An extraneous variable that varies systematically with the independent variable, making causal inference impossible.

Control Group: In an experiment, the group that does not receive the treatment being studied; provides a baseline for comparison.

Dependent Variable (DV): The response or behavior that the experimenter measures.

Description: A goal of science involving accurately portraying phenomena.

Determinism: The assumption that behavior is orderly and systematic, not random, and that every behavior has causes that can potentially be identified.

Discoverability: The assumption that it is possible to discover the orderly relationships governing behavior.

Disconfirmed: The status of a theory that has been contradicted by evidence; in science, theories can be supported or disconfirmed but never conclusively proven.

Empirical Observation: Observation based on sensory experience and data collection; the foundation of scientific knowledge.

Empiricism: The philosophical position that knowledge comes from sensory experience and observation.

Experimental Control: The systematic manipulation of one variable while holding everything else constant to isolate causal effects.

Experimental Design: A general plan for selecting participants, assigning participants to experimental conditions, controlling extraneous variables, and gathering data.

Experimental Group: In an experiment, the group that receives the treatment being studied.

Explanation: A goal of science involving understanding why phenomena occur by identifying causes and developing theories.

External Validity: The extent to which research findings generalize beyond the specific study to other populations, settings, and times.

Extraneous Variable: An undesired variable that may operate to influence the dependent variable and potentially invalidate an experiment.

F-ratio: In ANOVA, the ratio of variance between groups to variance within groups; a large F-ratio indicates the independent variable has an effect.

Factorial ANOVA: An inferential statistical test used to analyze data from factorial designs; tests main effects and interactions.

Factorial Design: An experimental design with more than one independent variable.

Factorial Mixed-Groups Design: A factorial design with at least one between-subjects IV and at least one within-subjects IV.

Generalization: Applying results from an experiment to different situations or populations.

Hypothesis: A testable prediction derived from a theory.

Independent Groups: Groups of research participants formed by random assignment; each participant appears in only one group.

Independent Variable (IV): The stimulus or aspect of the environment that the experimenter manipulates to determine its influence on behavior.

Interaction: In factorial designs, when the effect of one independent variable depends on the level of another independent variable.

Internal Validity: The extent to which an experiment demonstrates a causal relationship between the IV and DV, free from confounds and alternative explanations.

Lashley Jumping Stand: Apparatus developed by Karl Lashley to study discrimination learning; rats jump toward stimulus cards to reach food.

Law of Effect: Thorndike’s principle that responses producing satisfying consequences in a situation become more likely in that situation.

Levels: The differing amounts or types of an independent variable used in an experiment; also called treatment conditions.

Main Effect: In factorial designs, the overall effect of one independent variable, averaged across levels of other independent variables.

Manipulandum: The response device in an operant conditioning chamber, such as a lever for rats to press or a key for pigeons to peck.

Manipulation Check: A measure used to verify that the independent variable manipulation was effective; confirms that the IV actually changed what it was intended to change.

Matched Pairs: A method of creating related groups by measuring participants on some variable before the experiment and pairing similar participants.

Measurement Error: Inaccuracies in measurement; all measurements include truth plus error.

Methodological Determinism: Assuming determinism for research purposes while remaining agnostic about ultimate metaphysical questions of free will.

Method of Authority: A way of fixing belief by accepting ideas because trusted authority figures (experts, teachers, institutions) endorse them; efficient but fails when authorities are wrong.

Method of Tenacity: A way of fixing belief by holding firmly to ideas simply because one has always believed them; requires little cognitive effort and provides no mechanism for correcting false beliefs.

Morris Water Maze: Apparatus in which rats swim in opaque water to find a hidden platform; widely used to study spatial learning and hippocampal function.

Motor Skills Apparatus: Equipment such as mirror-tracing apparatus and pursuit rotors used to study motor skill acquisition.

Multiple Independent-Groups Design: A research design with more than two groups of participants formed by random assignment.

Natural Pairs: A method of creating related groups using participants who are naturally related, such as siblings or littermates.

One-Way ANOVA: Analysis of Variance for independent groups; a statistical test used when one IV has three or more groups formed by random assignment.

Operant Conditioning: A form of learning in which behavior is modified by its consequences; also called instrumental conditioning.

Operant Conditioning Chamber: Apparatus developed by B.F. Skinner for studying operant conditioning with automated recording and reinforcement delivery; informally called a Skinner box.

Operational Definition: A specification of how a variable is produced and measured in a particular study; defines concepts in terms of specific operations.

Parsimony: The scientific principle that when multiple explanations account for the data equally well, the simpler one should be preferred; also called Occam’s razor.

Pilot Study: A small-scale preliminary study conducted to test methodology rather than hypotheses; used to identify procedural problems before the main experiment.

Post hoc Test: A statistical comparison made between group means after finding a significant ANOVA to determine which specific groups differ.

Prediction: A goal of science involving anticipating when phenomena will occur based on theoretical understanding.

Puzzle Box: Apparatus developed by Thorndike to study trial-and-error learning; animals must discover how to escape to reach food.

Quasi-Experiment: A research design resembling a true experiment but lacking random assignment to conditions; can suggest but not definitively establish causal relationships.

Radial Arm Maze: Apparatus with multiple arms radiating from a central platform; used to study spatial working memory.

Random Assignment: A control technique ensuring each participant has an equal chance of being assigned to any group in the experiment.

Rationalism: The philosophical position that knowledge comes from logical reasoning.

Reinforcement: The process by which a consequence increases the likelihood of the behavior that produced it.

Related Groups: Groups of research participants that are related through repeated measures, matched pairs, or natural pairs.

Reliability: The ability to measure the same thing consistently over repeated measurements.

Repeated Measures: A method of creating related groups by testing the same participants in multiple conditions.

Serendipity: An accidental or unexpected discovery in research; finding something valuable while looking for something else (e.g., Pavlov discovering classical conditioning while studying digestion).

Single-Subject Design: An experimental design that intensively studies individual participants through repeated measurement across baseline and treatment phases; also called single-case or N=1 designs.

Statistical Power: The probability of detecting an effect when one truly exists; related groups designs typically have greater power than independent groups designs.

Statistical Significance: The determination that an observed result is unlikely to have occurred by chance alone.

T-Maze: A simple maze with a single choice point where the animal turns left or right.

t-test for Independent-Samples: An inferential statistic used to evaluate the difference between two means from randomly assigned groups.

t-test for Related-Samples: An inferential statistic used to evaluate the difference between two means from related groups; also called paired-samples t-test.

Theory: A set of interrelated concepts and propositions that present a systematic view of phenomena by specifying relationships among variables.

Tukey’s HSD: Honestly Significant Difference; a commonly used post hoc test that controls for multiple comparisons.

Two Independent-Groups Design: A research design with two groups of participants formed by random assignment.

Two Related-Groups Design: A research design with two groups of participants formed using repeated measures, matched pairs, or natural pairs.

Unconditioned Response: In classical conditioning, the natural, unlearned response elicited by the unconditioned stimulus.

Unconditioned Stimulus: In classical conditioning, a stimulus that naturally elicits a response without prior learning.

Validity: The ability to measure the construct you intended to measure.

Verbal Learning Equipment: Apparatus such as memory drums used to study human memory, often with nonsense syllables as stimuli.

Within-Subjects Factor: An independent variable for which the same participants experience all levels; also called repeated measures factor.

Working Memory: The cognitive system responsible for temporarily holding and manipulating information; tested by radial arm maze performance.

Y-Maze: A maze with three arms radiating from a central choice point.