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mixed-effects model

any statistical procedure or experimental design that uses one or more independent variables whose levels are specifically selected by the researcher (fixed effects; e.g., gender) and one or more additional independent variables whose levels are chosen randomly from a wide range of possible values (random effects; e.g., age). Also called mixed model. Compare fixed-effects model; random-effects model.

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Psychology term of the day

January 30th 2025

antibiotic

antibiotic

n. a drug used to destroy pathogenic or otherwise harmful microorganisms, especially bacteria. Antibiotics can be produced by or obtained from living cells (e.g., molds, yeasts, bacteria) or manufactured as synthetic chemicals with effects similar to natural antibiotics. Some work by interfering with bacterial reproduction, whereas others may disrupt the normal life functions of the pathogen. Antibiotics are ineffective against viruses. Overuse and inappropriate use of these agents are contributing to the development of bacterial resistance to many commonly used antibiotics.