153 How would you explain covariance to someone who understands only the mean? 2011-11-07T19:41:45.283

81 What's the difference between variance and standard deviation? 2012-08-26T12:31:04.077

65 Understanding "variance" intuitively 2011-10-25T21:28:47.460

55 How exactly did statisticians agree to using (n-1) as the unbiased estimator for population variance without simulation? 2014-05-26T00:09:19.983

45 Does the variance of a sum equal the sum of the variances? 2012-06-26T22:44:30.420

44 When conducting a t-test why would one prefer to assume (or test for) equal variances rather than always use a Welch approximation of the df? 2010-07-20T14:19:41.383

43 Computing Cohen's Kappa variance (and standard errors) 2012-06-17T00:37:51.407

40 What is the difference between N and N-1 in calculating population variance? 2011-11-03T15:02:53.050

38 Intuitive explanation of the bias-variance tradeoff? 2010-11-07T10:57:29.053

37 Variance and bias in cross-validation: why does leave-one-out CV have higher variance? 2013-06-14T20:14:49.827

31 Variance on the sum of predicted values from a mixed effect model on a timeseries 2011-05-18T14:59:03.320

30 What is the difference between a population and a sample? 2010-07-20T11:07:42.403

29 Variance of product of multiple random variables 2013-03-18T23:41:09.307

29 How can a distribution have infinite mean and variance? 2014-03-27T04:49:19.810

29 Why shouldn't the denominator of the covariance estimator be n-2 rather than n-1? 2015-03-19T13:13:01.890

28 Test for finite variance? 2010-09-09T06:01:05.300

28 Variance of a function of one random variable 2010-12-28T14:13:16.227

26 Variance of product of dependent variables 2011-09-23T16:23:41.887

26 (Why) do overfitted models tend to have large coefficients? 2013-07-13T01:30:46.463

26 Does $K$-fold CV with $K=N$ (LOO) provide the MOST or LEAST variable estimates, and what is the role of "stability"? 2017-05-20T01:11:46.233

24 How does one measure the non-uniformity of a distribution? 2012-04-04T09:00:33.637

24 Confidence Interval for variance given one observation 2012-12-02T00:09:22.587

24 Why does increasing the sample size lower the (sampling) variance? 2014-12-21T00:01:19.487

23 Existence of the moment generating function and variance 2012-07-20T16:30:49.167

22 Is variation the same as variance? 2014-03-01T07:28:46.633

22 Derive Variance of regression coefficient in simple linear regression 2014-03-02T15:56:38.557

22 What is the difference between finite and infinite variance 2014-04-19T22:16:24.700

22 Why do we take the square root of variance to create standard deviation? 2017-03-23T17:53:20.910

21 How to test equality of variances with circular data 2012-07-14T20:58:35.097

21 Standard deviation of binned observations 2013-05-28T16:57:11.487

21 Why does the variance of a sample change if the observations are duplicated? 2015-06-20T05:59:21.320

21 Showing that 100 measurements for 5 subjects provide much less information than 5 measurements for 100 subjects 2017-07-30T18:17:28.477

20 Bias correction in weighted variance 2013-01-09T15:35:11.193

19 Coefficient of Determination ($r^2$): I have never fully grasped the interpretation 2010-08-09T14:52:42.430

19 How to calculate pooled variance of two groups given known group variances, means, and sample sizes? 2012-11-08T17:02:50.250

19 Antonym of variance 2015-11-25T11:25:39.887

19 Why isn't variance defined as the difference between every value following each other? 2016-07-26T16:46:29.843

18 Link between variance and pairwise distances within a variable 2011-12-21T14:11:13.437

18 Why is regression about variance? 2012-07-06T23:15:05.430

18 Variance of a bounded random variable 2012-12-10T13:39:00.210

18 Asymptotic consistency with non-zero asymptotic variance - what does it represent? 2014-10-18T19:11:14.790

18 Is variance a more fundamental concept than standard deviation? 2016-06-09T03:16:35.977

17 Principal component analysis "backwards": how much variance of the data is explained by a given linear combination of the variables? 2011-03-22T14:00:23.313

17 What's the difference between the variance and the mean squared error? 2015-03-05T19:27:33.480

16 Maximum value of coefficient of variation for bounded data set 2011-11-19T04:26:40.343

16 Is there a graphical representation of bias-variance tradeoff in linear regression? 2011-11-29T15:08:39.557

16 Why Levene test of equality of variances rather than F ratio? 2012-03-02T21:59:51.150

16 Intuition (geometric or other) of $Var(X) = E[X^2] - (E[X])^2$ 2017-01-03T18:40:19.067

16 Intuitive explanation of the $(X^TX)^{-1}$ term in the variance of least square estimator 2017-03-16T19:05:20.097

15 Why do we stabilize variance? 2012-12-18T14:44:59.177

15 Bound for Arithmetic Harmonic mean inequality for matrices? 2013-08-21T23:19:11.713

15 In simple linear regression, where does the formula for the variance of the residuals come from? 2014-09-10T17:43:47.563

15 Why is the standard deviation defined as sqrt of the variance and not as the sqrt of sum of squares over N? 2014-09-22T17:10:30.133

14 How to estimate variance components with lmer for models with random effects and compare them with lme results 2012-06-26T10:02:58.663

14 What prior distributions could/should be used for the variance in a hierarchical bayesisan model when the mean variance is of interest? 2012-11-04T21:19:38.693

14 Why is chi square used when creating a confidence interval for the variance? 2013-11-13T12:22:33.907

14 How to detect polarized user opinions (high and low star ratings) 2014-06-05T22:08:15.520

14 Predicting variance of heteroscedastic data 2014-06-11T03:00:25.130

14 Asymptotic distribution of sample variance of non-normal sample 2014-07-01T00:38:35.430

14 Statistical variation in two Formula 1 qualifying formats 2016-04-04T13:06:52.903

14 For what models does the bias of MLE fall faster than the variance? 2017-01-18T08:08:37.047

13 Calculating required sample size, precision of variance estimate? 2011-02-09T00:48:49.097

13 Proportion of explained variance in a mixed-effects model 2011-02-15T09:11:10.857

13 How to use Levene test function in R? 2011-09-18T15:06:33.893

13 Statistical measure for if an image consists of spatially connected separate regions 2012-06-08T12:22:21.507

13 Weighted Variance, one more time 2013-03-06T06:50:54.207

13 Law of total variance as Pythagorean theorem 2013-10-01T19:51:58.297

13 Why does sphericity diagnosed by Bartlett's Test mean a PCA is inappropriate? 2014-04-07T06:00:17.930

13 What criteria must be met in order to conclude a 'ceiling effect' is occurring? 2014-05-07T08:30:12.273

13 Is there any required amount of variance captured by PCA in order to do later analyses? 2015-01-14T20:32:25.610

13 What is importance sampling? 2017-01-02T07:57:51.780

12 What is the precise definition of a "Heywood Case"? 2010-10-30T21:31:17.513

12 What is the probability that a normal distribution with infinite variance has a value greater than its mean? 2011-03-14T16:19:27.127

12 Parametric modelling of variance of count data 2011-10-19T21:21:28.453

12 Variance of product of k correlated random variables 2013-05-30T06:13:27.517

12 Is there a measure of 'evenness' of spread? 2014-11-04T18:53:29.720

12 What is the long run variance? 2015-05-21T20:12:23.307

12 I don't understand the variance of the binomial 2017-05-15T15:59:04.877

11 What is the practical application of variance? 2011-04-28T04:51:05.910

11 How to calculate the variance of a partition of variables 2011-05-06T20:27:01.463

11 What is the variance of the maximum of a sample? 2011-09-23T14:16:33.863

11 What is the difference between sample variance and sampling variance? 2011-10-14T02:53:13.780

11 How to conceptualize error in a regression model? 2012-02-08T01:36:58.393

11 Does transformation of r into Fisher z benefit a meta-analysis? 2012-04-15T05:32:41.360

11 Expected value and variance of trace function 2012-08-16T20:33:49.323

11 Reference for $\text{Var}(X)\le (b-a)^2/4$ 2013-02-21T16:54:24.950

11 Variance of annual return based on variance of monthly return 2013-07-12T18:18:06.653

11 Intuitive reason why the Fisher Information of Binomial is inversely proportional to $p(1-p)$ 2013-12-30T19:05:31.197

11 Do the mean and the variance always exist for exponential family distributions? 2014-03-20T15:55:17.590

11 Deduce variance from boxplot 2014-03-27T11:15:45.987

11 Variance of Cohen's $d$ statistic 2015-03-30T16:22:14.660

11 Why Are Measures of Dispersion Less Intuitive Than Centrality? 2015-11-23T20:41:12.397

11 Why would Netflix switch from its five-star rating system to a like/dislike system? 2017-04-11T18:20:45.213

10 Are these formulas for transforming P, LSD, MSD, HSD, CI, to SE as an exact or inflated/conservative estimate of $\hat{\sigma}$ correct? 2010-09-20T23:14:27.380

10 When would it be appropriate to report variance instead of standard deviation? 2011-03-21T19:51:20.863

10 Reference for $\mathrm{Var}[s^2]=\sigma^4 \left(\frac{2}{n-1} + \frac{\kappa}{n}\right)$? 2012-06-06T14:49:48.137

10 In a one sample t-test, what happens if in the variance estimator the sample mean is replaced by $\mu_0$? 2014-01-30T14:47:42.600

10 Variance inflation factor for generalized additive models 2014-04-08T15:40:19.657

10 Determinant of Fisher information 2014-08-30T09:12:13.683