Longitudinal
(adjective)
 Sampling data over time rather than merely once.
Examples of Longitudinal in the following topics:
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Methods for Researching Human Development- These include longitudinal, cross-sectional, sequential, and microgenetic designs.
- In a longitudinal study, a researcher observes many individuals born at or around the same time (a cohort) and carries out new observations as members of the cohort age.
- Longitudinal studies often require large amounts of time and funding, making them unfeasible in some situations.
- Cross-sequential designs combine both longitudinal and cross-sectional design methodologies.
- In a longitudinal study, a researcher observes many individuals born at or around the same time and observes them as they age.
 
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Generalized Anxiety Disorder- Indeed, one longitudinal study found that childhood maltreatment was strongly related to the development of this disorder during adulthood (Moffitt et al., 2007).