Statistical analysis plays a crucial role in experimental design. Two main types of statistical methods commonly used for analyzing experimental data are descriptive statistics and inferential statistics. Descriptive statistics are used to describe, organize, and summarize data. This includes measures of central tendency (such as the mean and median) and measures of relative position and variability (such as range, standard deviation, and coefficient of variation). In descriptive statistics, data from all participants in the sample are expressed numerically—for example, by presenting the mean and standard deviation.