data dealing with numeric values that are either calculated or are calculable. Measurements and computations are typical examples: "Net-Pay," "Quantity Ordered," "Elapsed Time," "Percent of Gross," etc. It is sometimes difficult to differentiate Quantitative data from Indicative data. Indicative data will often use numeric values for identification purposes, such as "Invoice Number," "Purchase Order Number," "Customer Number," etc. However, it would be a mistake to use these numbers for quantitative purposes (aside from counting the number of occurrences). (See Descriptive Data and Indicative Data).