block design

a type of research study in which participants are divided into relatively homogeneous subsets (blocks) from which they are assigned to the experimental or treatment conditions. For example, in a simple block design to evaluate the efficacy of several antidepressants, participants with similar pretest depression scores might be grouped into homogeneous blocks and then assigned to receive different medications. The purpose of a block design is to ensure that a characteristic of the study participants that is related to the target outcome (i.e., a covariate) is distributed equally across treatment conditions. See complete block design; incomplete block design; randomized block design.

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Psychology term of the day

January 30th 2025

realistic group conflict theory

a conceptual framework predicated on the assumption that intergroup tensions will occur whenever social groups must compete for scarce resources (e.g., food, territory, jobs, wealth, power, natural resources) and that this competition fuels prejudice and other antagonistic attitudes that lead to conflicts such as rivalries and warfare. Also called realistic conflict theory.