A statistical data set that typically uses the average value of the results of any research methodology over time as a standard by which new data collected, using the same methodology, can be compared. Norms are often used for copy testing methodologies or attitude tracking studies, to statistically compare the results of a new ad test to a historic data set. (See also “Benchmark(s)”). Benchmarks can be proprietary or public depending on the type of benchmark data being evaluated.