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Levinson’s adult development theory

a model of human development in which adulthood is divided into early, middle, and late segments, each period consisting of (a) transitional, or entry, stages (e.g., age-30 transition, age-40 transition), which are often times of uncertainty, self-examination, exploration, and modification of the quality and significance of life commitments, and (b) intervening periods of relative stability, when individuals consolidate new interpretations, structures, and goals and move forward. The adaptations associated with transitional periods may be relatively smooth and uneventful or may be experienced as psychologically difficult and painful (e.g., as a midlife crisis). [proposed by Daniel Levinson (1920–1994), U.S. psychologist]

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Psychology term of the day

February 25th 2025

single-case design

single-case design

an approach to the empirical study of a process that tracks a single unit (e.g., person, family, class, school, company) in depth over time. Specific types include the alternating treatments design, the multiple baseline design, the reversal design, and the withdrawal design. In other words, it is a within-subjects design with just one unit of analysis. For example, a researcher may use a single-case design for a small group of patients with a tic. After observing the patients and establishing the number of tics per hour, the researcher would then conduct an intervention and watch what happens over time, thus revealing the richness of any change. Such studies are useful for generating ideas for broader studies and for focusing on the microlevel concerns associated with a particular unit. However, data from these studies need to be evaluated carefully given the many potential threats to internal validity; there are also issues relating to the sampling of both the one unit and the process it undergoes. Also called N-of-1 design; N=1 design; single-participant design; single-subject (case) design.