Statistical significance is a measure of how likely it is that an observed relationship between two or more variables is caused by something other than chance. In simpler terms, it is a determination of whether the data supports the hypothesis rather than the null hypothesis. Statistical significance is the key difference between a meaningful result and an insignificant one.

Statistical significance is typically measured using a p-value. The p-value is an index that measures the probability of a result occurring randomly or due to chance. It is given as a decimal, usually in the range of 0 - 1, although it can sometimes be expressed as a percentage. A p-value of 0.05 or lower is generally considered statistically significant, meaning that there is only a 5% probability that the result is due to chance.

In order to determine whether a result is statistically significant, researchers will often conduct a statistical hypothesis test such as the chi-square test, Student's t-test, or F-test. Each of these tests follows a similar process, which involves forming a null hypothesis, gathering the data, performing the appropriate test statistic calculations, and finally, using the p-value to make a conclusion.

Statistical significance is an important concept in data analysis, as it allows researchers to draw meaningful conclusions from their data. It helps researchers to identify meaningful relationships that may have gone unnoticed without the use of such testing. It is also used as a guide for decision making, such as whether to accept or reject a certain hypothesis or to choose a certain course of action.

Ultimately, statistical significance allows researchers and decision makers to make accurate judgments about their data. It allows them to infer meaningful relationships from the data and use them to make more informed decisions. The use of statistical tests and p-values provide researchers and decision makers with the evidence and confidence needed to make sound decisions, from small decisions such as which marketing strategy to pursue, to larger decisions such as whether or not to fund a study.