Statistical Significance

This chapter highlights statistical significance. The key question in quantitative analysis is whether a pattern observed in a sample also holds for the population from which the sample was drawn. A positive answer to this question implies that the result is ‘statistically significant’ — i.e. it was not produced by a random variation from sample to sample, but, instead, reflects the pattern that exists in the population. The null hypothesis statistical test (NHST) has been a widely used approach for testing whether inference from a sample to the population is valid. Seeking to test whether valid inferences about the population could be made based on the results from a single sample, a researcher should consider a wide variety of approaches and take into the account not only p-values, but also sampling process, sample size, the quality of measurement, and other factors that may influence the reliability of estimates.