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Glossary 1.8 Glossary
- anecdotal evidence.
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Data collected informally from a small number of individual cases, often without systematic sampling.
- cross-sectional study.
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A study that collects data from a representative sample of a population at a single point or interval in time.
- cycle.
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One data-collection interval in a study that collects data at multiple intervals in time.
- population.
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The entire group of individuals or items that is the subject of a study.
- sample.
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A subset of a population, often chosen at random.
- respondents.
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People who participate in a survey and respond to questions.
- representative.
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A sample is representative if it is similar to the population in ways that are important for the purposes of the study.
- stratified.
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A sample is stratified if it deliberately oversamples some groups, usually to make sure that enough members are included to support valid conclusions.
- oversampled.
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A group is oversampled if its members have a higher chance of appearing in a sample.
- variable.
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In survey data, a variable is a collection of responses to questions or values computed from responses.
- codebook.
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A document that describes the variables in a dataset, and provides other information about the data.
- recode.
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A variable that is computed based on other variables in a dataset.
- raw data.
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Data that has not been processed after collection.
- data cleaning.
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A process for identifying and correcting errors in a dataset, dealing with missing values, and computing recodes.
- statistic.
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A value that describes or summarizes a property of a sample.
- standard deviation.
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A statistic that quantifies the spread of data around the mean.
