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Everything about Variance

Statistical measure of how far values spread from their average

In probability theory and statistics, variance is a measure of dispersion, meaning it is a measure of how far a set of numbers are spread out from their average value. It is defined as the expected value of the squared deviation from the mean of a random variable. The standard deviation is the square root of the variance. Technically, it is the second central moment of a distribution, and the covariance of the random variable with itself, and it is often represented by ⁠⁠, ⁠⁠, ⁠⁠, ⁠⁠, or ⁠⁠. Wikipedia →

🧭 Start here: a 6-step reading path

  1. Read the overview: VarianceA 5-minute orientation
  2. Skim a recent paper: Bias correction for inverse variance weighting Mendelian randomizationInfluential work since 2022
  3. Pick up a classic book: Extending the Linear Model with RThe most-reprinted book on the subject
  4. Read the landmark paper: A new criterion for assessing discriminant validity in variance-based structural equation modelingCited 34,639 times
  5. Go sideways: Covariance matrixA closely related topic
  6. Go sideways: CovarianceA closely related topic

📖 Definitions

Noun The act of varying or the state of being variable.

Noun A difference between what is expected and what is observed; deviation.

Noun The state of differing or being in conflict.

Noun An official permit to do something that is ordinarily forbidden by regulations.

🏆 Landmark papers (most cited)

🆕 Influential since 2022

📚 Books worth reading

Ranked by number of editions on Open Library, a rough measure of how lasting a book is.

🔗 Related topics