What is a characteristic on which elements of a population or sample differ from each other?

A characteristic on which elements of a population or sample differ from each other is referred to as a variable. In statistical terms, a variable is any measurable attribute that can take on different values among individuals or units in the dataset. This could include characteristics such as height, age, or income, where each element can exhibit a range of values.

Variables are essential in both descriptive and inferential statistics. They allow analysts to describe the population using summary statistics and to conduct hypothesis testing. Understanding variables is crucial for determining relationships and patterns within the data, which is a key aspect of data analysis disciplines, including quality management methodologies utilized in projects like Six Sigma.

In contrast, a constant denotes a fixed value that does not change across the data set. Parameters and statistics are different in that they refer to specific values calculated from a population or sample, respectively, rather than the characteristics themselves that exhibit variability.