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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. List of statistical tests - Wikipedia

    en.wikipedia.org/wiki/List_of_statistical_tests

    They also have the disadvantage of being less certain in the statistical estimate. [7] Type of data: Statistical tests use different types of data. [1] Some tests perform univariate analysis on a single sample with a single variable. Others compare two or more paired or unpaired samples. Unpaired samples are also called independent samples.

  4. Sampling (statistics) - Wikipedia

    en.wikipedia.org/wiki/Sampling_(statistics)

    For example, in an opinion poll, possible sampling frames include an electoral register and a telephone directory. A probability sample is a sample in which every unit in the population has a chance (greater than zero) of being selected in the sample, and this probability can be accurately determined. The combination of these traits makes it ...

  5. 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.

  6. 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 ...

  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. Factor analysis - Wikipedia

    en.wikipedia.org/wiki/Factor_analysis

    Use quantitative marketing research techniques (such as surveys) to collect data from a sample of potential customers concerning their ratings of all the product attributes. Input the data into a statistical program and run the factor analysis procedure. The computer will yield a set of underlying attributes (or factors).

  9. Statistics - Wikipedia

    en.wikipedia.org/wiki/Statistics

    Two main statistical methods are used in data analysis: descriptive statistics, which summarize data from a sample using indexes such as the mean or standard deviation, and inferential statistics, which draw conclusions from data that are subject to random variation (e.g., observational errors, sampling variation). [4]