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  2. Retrospective cohort study - Wikipedia

    en.wikipedia.org/wiki/Retrospective_cohort_study

    A retrospective cohort study, also called a historic cohort study, is a longitudinal cohort study used in medical and psychological research. A cohort of individuals that share a common exposure factor is compared with another group of equivalent individuals not exposed to that factor, to determine the factor's influence on the incidence of a ...

  3. Research design - Wikipedia

    en.wikipedia.org/wiki/Research_design

    A research design typically outlines the theories and models underlying a project; the research question(s) of a project; a strategy for gathering data and information; and a strategy for producing answers from the data. [1] A strong research design yields valid answers to research questions while weak designs yield unreliable, imprecise or ...

  4. Cohort study - Wikipedia

    en.wikipedia.org/wiki/Cohort_study

    Cohort studies represent one of the fundamental designs of epidemiology which are used in research in the fields of medicine, pharmacy, nursing, psychology, social science, and in any field reliant on 'difficult to reach' answers that are based on evidence . In medicine for instance, while clinical trials are used primarily for assessing the ...

  5. Longitudinal study - Wikipedia

    en.wikipedia.org/wiki/Longitudinal_study

    A longitudinal study (or longitudinal survey, or panel study) is a research design that involves repeated observations of the same variables (e.g., people) over long periods of time (i.e., uses longitudinal data). It is often a type of observational study, although it can also be structured as longitudinal randomized experiment. [1]

  6. Regression discontinuity design - Wikipedia

    en.wikipedia.org/.../Regression_discontinuity_design

    The RD design takes the shape of a quasi-experimental research design with a clear structure that is devoid of randomized experimental features. Several aspects deny the RD designs an allowance for a status quo. For instance, the designs often involve serious issues that do not offer room for random experiments.

  7. Temporal difference learning - Wikipedia

    en.wikipedia.org/wiki/Temporal_difference_learning

    Temporal difference (TD) learning refers to a class of model-free reinforcement learning methods which learn by bootstrapping from the current estimate of the value function. These methods sample from the environment, like Monte Carlo methods , and perform updates based on current estimates, like dynamic programming methods.

  8. Cross-sectional study - Wikipedia

    en.wikipedia.org/wiki/Cross-sectional_study

    In medical research, epidemiology, social science, and biology, a cross-sectional study (also known as a cross-sectional analysis, transverse study, prevalence study) is a type of observational study that analyzes data from a population, or a representative subset, at a specific point in time—that is, cross-sectional data.

  9. Time preference - Wikipedia

    en.wikipedia.org/wiki/Time_preference

    This setup establishes a tradeoff between current value (money now) vs future value (savings later). One paper analyzed a survey of air conditioner purchases using a hedonic pricing method. [ 27 ] Essentially, “the price of a good is specified as a function of a set of its attributes,” and they find that the discount rate is 13.6%.