The independent t-test (also known as an independent-samples t-test, independent-measures t-test or unpaired t-test) determines whether there is a statistically significant difference in the mean of a dependent variable between two unrelated, independent groups....
Note: In Stata 12, you will see that the independent t-test is referred to as the "two-group mean-comparison test", whereas in Stata 13, it is referred to as the "t test (mean-comparison test)".In this guide, we show you how to carry out an independent t-test using Stata, as...
Because the independent-samples t test compares group means, it follows that outliers are also a problem for the t test. As noted earlier, handling outliers can be problematic. For some kinds of variance (such as salary or reaction time) you can anticipate that outliers are likely, and in ...
The more the populations depart from normality, the larger the sample size needed for the Central Limit Theorem to weave its magic, but we've seen examples to suggest that 100 observations per group is often quite sufficient. For small and moderate sample sizes, the equal variances version of...
We also identified examples of heterofertilization in Arabidopsis, including the mechanism, which involves a higher percentage of the second-pollen-tube attraction due to a weak polytubey block by the single fertilization events. Results and Discussion Arabidopsis Has a Dual-Control Polytubey Blocking...
In conclusion, the Eigenmannia species group has provided several independent examples of the rapid evolution of sex chromosomes and of chromosomal rearrangements (Almeida-Toledo et al., 2000, 2001, 2002; Almeida-Toledo and Foresti, 2001; Henning et al., 2008). The combined approach of ...
S≤T⇔0≤T−S. Examples 1 (Self-Adjoint and Normal Operators) (a) The identity I and zero operator O are self-adjoint. (b) If a finite-dimensional linear operator A on Cn is represented by a matrix A, its adjoint corresponds to the matrix AH. The operator is self-adjoint iff ...
How the vast majority of B cells express only one of the two alleles at their immunoglobulin loci remains a biological puzzle. Here, in mice reconstituted with a single haematopoietic stem cell, we demonstrate that each of the two immunoglobulin heavy ch
For example, there must be different participants in each group with no participant being in more than one group. This is more of a study design issue than something you can test for, but it is an important assumption of the independent t-test. If your study fails this assumption, you ...
Although more than half of all genes generate transcripts that differ in 3′UTR length, current analysis pipelines only quantify the amount but not the length of mRNA transcripts. 3′UTR length is determined by 3′ end cleavage sites (CS). We map CS