Tag: t-test

198 What is the meaning of p values and t values in statistical tests? 2010-07-19T19:28:44.903

74 How to choose between t-test or non-parametric test e.g. Wilcoxon in small samples 2014-10-29T03:02:19.667

61 T-test for non normal when N>50? 2011-04-14T21:55:43.747

54 Is there a minimum sample size required for the t-test to be valid? 2012-09-25T23:42:35.733

53 Why is it possible to get significant F statistic (p<.001) but non-significant regressor t-tests? 2010-10-13T09:40:17.420

49 Which permutation test implementation in R to use instead of t-tests (paired and non-paired)? 2011-01-10T12:10:29.000

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

37 How should one interpret the comparison of means from different sample sizes? 2012-06-29T01:24:40.470

37 How are regression, the t-test, and the ANOVA all versions of the general linear model? 2013-05-15T00:46:04.307

36 If the t-test and the ANOVA for two groups are equivalent, why aren't their assumptions equivalent? 2010-08-13T09:41:13.160

35 How to test hypothesis of no group differences? 2010-09-24T05:24:00.240

33 Significance of coefficients in linear regression: significant t-test vs non-significant F-statistic 2012-03-15T19:56:37.380

32 Manually Calculating P value from t-value in t-test 2012-12-05T01:51:06.733

28 Can ANOVA be significant when none of the pairwise t-tests is? 2014-01-22T16:25:55.920

28 Bayesian equivalent of two sample t-test? 2014-12-26T19:06:05.300

26 How to statistically compare the performance of machine learning classifiers? 2012-12-13T16:20:14.137

26 Distinguishing between two groups in statistics and machine learning: hypothesis test vs. classification vs. clustering 2017-02-18T16:27:38.220

25 When to use the Wilcoxon rank-sum test instead of the unpaired t-test? 2011-12-11T21:13:41.320

24 How to perform Student's t-test having only sample size, sample average and population average are known? 2010-08-18T01:39:31.013

24 Have the reports of the death of the t-test been greatly exaggerated? 2015-11-25T01:27:06.737

23 t-test for partially paired and partially unpaired data 2012-04-05T21:54:16.657

22 Group differences on a five point Likert item 2010-07-20T03:31:45.820

22 How robust is the independent samples t-test when the distributions of the samples are non-normal? 2012-10-09T00:29:25.453

21 How to perform two-sample t-tests in R by inputting sample statistics rather than the raw data? 2012-06-13T16:15:52.413

18 Paired versus unpaired t-test 2012-09-27T12:24:56.663

17 How does the power of a logistic regression and a t-test compare? 2010-10-28T18:33:14.513

17 How to test for differences between two group means when the data is not normally distributed? 2011-09-16T15:59:13.033

17 What sense does it make to compare p-values to each other? 2012-01-20T21:03:53.123

17 Is there a statistical test to compare two samples of size 1 and 3? 2012-11-27T01:30:24.623

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

16 t-test on highly skewed data 2013-09-12T20:53:24.693

15 Minimum sample size for unpaired t-test 2012-01-21T22:24:12.050

15 Is a log transformation a valid technique for t-testing non-normal data? 2012-04-02T23:10:37.627

15 Is "test statistic" a value or a random variable? 2014-02-04T18:14:02.953

15 Choosing between $z$-test and $t$-test 2014-02-07T19:29:11.853

15 Is Student's t test a Wald test? 2014-09-13T18:06:50.117

15 Can I trust a significant result of a t-test if the sample size is small? 2017-03-06T23:13:39.737

14 Robust t-test for mean 2010-08-07T05:18:58.967

14 Comparing two classifier accuracy results for statistical significance with t-test 2012-04-11T14:05:59.310

13 Is there any difference between the terms "paired t-test" and "pairwise t-test"? 2011-02-16T04:34:46.397

13 Logistic regression or T test? 2015-06-29T01:54:38.310

13 Independent samples t-test: Do data really need to be normally distributed for large sample sizes? 2016-03-30T17:17:36.967

13 Why do t-test and ANOVA give different p-values for two-group comparison? 2017-03-10T15:19:06.597

12 Express answers in terms of original units, in Box-Cox transformed data 2010-08-15T17:01:49.620

12 Etymology of "t" in t-test and t-distribution 2012-01-15T16:26:11.237

12 Paired t-test as a special case of linear mixed-effect modeling 2012-02-21T23:31:57.257

12 What to do when the means of two samples are significantly different but the difference seems too small to matter 2012-07-06T09:34:31.337

12 How much smaller can $p$ values from ANOVA's $F$-test be vs. those from multiple $t$-tests on the same data? 2014-01-23T16:01:47.140

12 Should I use t-test on highly skewed data ? Scientific proof, please? 2014-08-05T22:56:20.093

12 Test model coefficient (regression slope) against some value 2014-08-12T11:14:39.673

12 What follows if we fail to reject the null hypothesis? 2015-07-30T14:54:00.070

12 Assessments of "Approximately Normal" for t-tests 2015-09-25T12:17:49.643

12 Common statistical tests as linear models 2017-09-15T07:53:19.707

11 Two-sample T-test with weighted data 2010-08-03T22:56:48.420

11 Sample size required to determine which of a set of advertisements has the highest click through rate 2011-03-10T14:52:20.337

11 What is the Bayesian counterpart to a two-sample t-test with unequal variances? 2011-09-20T02:43:16.587

11 What normality assumptions are required for an unpaired t-test? And when are they met? 2011-12-11T19:04:14.013

11 Explanation for non-integer degrees of freedom in t test with unequal variances 2014-09-23T20:31:19.743

11 Reporting degrees of freedom for Welch t-test 2014-11-21T13:54:07.210

11 Is it wrong to use ANOVA instead of a t-test for comparing two means? 2016-09-25T22:47:20.807

10 How to perform t-test with huge samples? 2010-10-30T07:55:10.057

10 Can I use a paired t-test when the samples are normally distributed but their difference is not? 2011-09-22T19:56:34.800

10 Are the degrees of freedom for Welch's test always less than the DF of the pooled test? 2013-01-27T17:21:19.317

10 "Accept null hypothesis" or "fail to reject the null hypothesis"? 2013-06-02T16:52:08.493

10 $t$-tests vs $z$-tests? 2013-06-09T12:54:58.060

10 Should I use Welch's (1947) approximate degrees of freedom or Satterthwaite's (1946)? 2013-09-24T22:22:48.957

10 Test if people drop out or decrease bets after repeated losses 2013-11-14T19:48:57.557

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 How can a t-test be statistically significant if the mean difference is almost 0? 2014-02-25T20:09:51.540

10 Statistical significance of difference between distances 2016-11-20T18:48:55.417

9 Does this single value match that distribution? 2013-06-26T13:05:09.987

9 In what settings would confidence intervals not get better as sample size increases? 2013-08-04T00:17:16.983

9 t.test returns an error "data are essentially constant" 2014-08-23T05:33:34.820

9 Question about normality assumption of t-test 2015-03-11T14:52:25.707

9 Why is the degrees of freedom for a matched pairs $t$-test the number of pairs minus 1? 2016-04-30T01:40:05.153

9 In what situation would Wilcoxon's Signed-Rank Test be preferable to either t-Test or Sign Test? 2016-11-22T10:08:58.927

8 How could a Tukey HSD test be more signif then the uncorrected P value of t.test? 2011-02-05T15:42:04.080

8 Why is a t-test necessary given that we have the z-test? 2011-09-30T06:37:19.580

8 Difference between t-test and ANOVA in linear regression 2011-10-13T08:45:53.050

8 How best to analyze length of stay data in a hospital-based RCT? 2011-12-12T16:32:52.633

8 Welch's t-test gives worse p-value for more extreme difference 2012-05-09T04:35:10.870

8 Minimum number of observations for multiple linear regression 2012-06-01T08:25:35.110

8 Can I do a t test if I have little to no variance in one group? 2012-06-13T16:25:04.953

8 Mean comparisons following multiple imputation 2012-08-10T16:05:38.290

8 When is the distribution of $(\overline{x}-\mu)/{\rm SE}(\overline{x})$ normal and when is it $t$? 2012-08-21T11:22:23.853

8 Small and unbalanced sample sizes for two groups - what to do? 2012-12-11T13:29:48.713

8 Can a sample be too large for ANOVA or a t-test? 2013-04-11T21:03:27.043

8 Why is dependence a problem? 2013-06-09T07:53:39.763

8 Power of a Mann Whitney test compared to a t test 2013-09-27T22:54:14.703

8 How to compare repeatability (ICC) of different groups? 2013-12-10T19:01:36.160

8 Does a big difference in sample sizes together with a difference in variances matter for a t-test (or permutation test)? 2014-02-19T21:28:10.323

8 Overlapping sample t-test 2014-03-26T15:28:18.237

8 When doing a t-test for the significance of a regression coefficient, why is the number of degrees of freedom $n-p-1$? 2014-04-09T06:11:08.077

8 Should I bother that t-test power is relatively small when H0 is already rejected? 2015-06-08T21:29:49.207

8 T-test using only summary data in a box plot 2015-09-03T21:14:14.227

8 How to visualize independent two sample t-test? 2016-01-11T20:21:49.923

8 Cohen's d for dependent sample t-test 2016-03-14T16:25:42.770

7 Interpreting two-sided, two-sample, Welch T-Test 2011-01-03T13:17:49.960

7 Hard exemplary problem sets to work through to solidify my understanding of statistical concepts? 2011-04-12T03:14:53.957