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  2. Instrumental variables estimation - Wikipedia

    en.wikipedia.org/wiki/Instrumental_variables...

    The strength of the instruments can be directly assessed because both the endogenous covariates and the instruments are observable. [20] A common rule of thumb for models with one endogenous regressor is: the F-statistic against the null that the excluded instruments are irrelevant in the first-stage regression should be larger than 10.

  3. Questionnaire - Wikipedia

    en.wikipedia.org/wiki/Questionnaire

    A questionnaire is a research instrument that consists of a set of questions (or other types of prompts) for the purpose of gathering information from respondents through survey or statistical study. A research questionnaire is typically a mix of close-ended questions and open-ended questions. Open-ended, long-term questions offer the ...

  4. Survey methodology - Wikipedia

    en.wikipedia.org/wiki/Survey_methodology

    Survey methodology is "the study of survey methods". [1] As a field of applied statistics concentrating on human-research surveys, survey methodology studies the sampling of individual units from a population and associated techniques of survey data collection, such as questionnaire construction and methods for improving the number and accuracy of responses to surveys.

  5. Research design - Wikipedia

    en.wikipedia.org/wiki/Research_design

    The choice of how to group participants depends on the research hypothesis and on how the participants are sampled.In a typical experimental study, there will be at least one "experimental" condition (e.g., "treatment") and one "control" condition ("no treatment"), but the appropriate method of grouping may depend on factors such as the duration of measurement phase and participant ...

  6. List of statistical tests - Wikipedia

    en.wikipedia.org/wiki/List_of_statistical_tests

    Statistical tests are used to test the fit between a hypothesis and the data. [1] [2] Choosing the right statistical test is not a trivial task. [1] The choice of the test depends on many properties of the research question. The vast majority of studies can be addressed by 30 of the 100 or so statistical tests in use. [3] [4] [5]

  7. Sample size determination - Wikipedia

    en.wikipedia.org/wiki/Sample_size_determination

    Sample size determination or estimation is the act of choosing the number of observations or replicates to include in a statistical sample.The sample size is an important feature of any empirical study in which the goal is to make inferences about a population from a sample.

  8. Data collection - Wikipedia

    en.wikipedia.org/wiki/Data_collection

    Example of data collection in the biological sciences: Adélie penguins are identified and weighed each time they cross the automated weighbridge on their way to or from the sea. [ 1 ] Data collection or data gathering is the process of gathering and measuring information on targeted variables in an established system, which then enables one to ...

  9. List of research methods in biology - Wikipedia

    en.wikipedia.org/wiki/List_of_research_methods...

    Statistical hypothesis test: Mann–Whitney U test: A statistical hypothesis test of the null hypothesis that, for randomly selected values X and Y from two populations, the probability of X being greater than Y is equal to the probability of Y being greater than X: Nonparametric statistics: Student's t-test