An important aspect of pairwise sequence comparison is assessing the statistical significance of the alignment. Most of the currently popular alignment programs report the statistical significance of an alignment in context of a database search. This database statistical significance is dependent on the database, and hence, the same alignment of a pair of sequences may be assessed different sta...

Background In science, statistics are universally used for making an inference about a population from sample data. The purpose of statistical inference is to determine if a proposed null hypothesis can be rejected, by comparing the probability of an observation to occur under the null hypothesis (p-value) to a chosen alpha level of confidence. The null hypothesis is rejected if the p-value is ...

Experimental design requires estimation of the sample size required to produce a meaningful conclusion. Often, experimental results are performed with sample sizes which are inappropriate to adequately support the conclusions made. In this paper, two factors which are involved in sample size estimation are detailed--namely type I (alpha) and type II (beta) error. Type I error can be considered ...

In observational studies, a statistically significant relationship can become statistically insignificant after taking into account the influence of a confounding factor. This is simply a result of the fact that in observational studies, all associations are contextual. Associations can change depending on what you take into account. First, a graph type is introduced that displays the influence...