Both variable data and attribute data measure the state of an object or a process, but the kind of information that each describes differs. Variable data involve numbers measured on a continuous scale, while attribute data involve characteristics or other information that you can't quantify. Each has its own benefits over the other.
Variable data include numerical measurements about a product or item, such as its size, weight or age. The measurements for a 70-inch television, foot-long ruler, or a turkey that weighs 10 pounds are all examples of variable data. You can also get averages from this kind of data, such as an average age for a population in a city or the average temperature on any given day of the year.
Attribute data consider the quality of a product or item rather than quantifiable numbers. They provide ancillary information about these things, such as the color or finish of a product. Attribute data may also include a count of some sort, such as the number of people who go to the movies, or how many products manufactured by a machine are defective. You cannot use attribute data to calculate other information, such as averages or rankings.
Benefits of Variable Data
Variable data provide detailed and concrete information about a product. In contrast, attribute data may be obscure or unhelpful. For example, if nails need to be made to a one-inch specification, with a leeway of 0.1-inches either way, variable data about each nail would provide the exact length. Attribute data would only state whether each nail fit the specification or not. It wouldn't state whether the nail was too long or too short.
Benefits of Attribute Data
Attribute data are often more helpful when qualitative information is needed. Examples include the state of an object, non-numerical characteristics and customer feedback. For example, the attribute data might count the number of people who shop at a specific store, or the size of a product, such as a small or large serving of food. Attribute data are useful for analysis as you can use attribute data to create ratios, percentages or charts, whereas variable data don't lend itself as freely to this.