The calibration of an analytical method is a very important part of its development, and only the proper statistical and chemometric evaluation of the results, together with understanding this process, allows good results. The purpose of this minireview is to call the reader's attention to the major problems in calibration: curvilinearity, heteroscedasticity, presence of outliers, transformation of results, and distribution and autocorrelation of residuals. The common misunderstandings and mistakes are emphasized to inform the reader. Additionally, the computational package "quantchem" for GNU R environment, allowing full and automatic calibration evaluation, is presented.