The most difficult part of conducting any type of evaluation is determining how well someone actually performed and then communicating that information in a meaningful way.
For example, suppose that Chris, a high school student can run a mile in 5 minutes. Most people would not find these numbers to be very meaningful. Is a 5-minute mile a poor time for a teenager running a mile or should Chris consider a running career?
A logical question to ask about the performance of Chris is “Is that good or bad?”
This example uses what is known as a “raw score.” A raw score is the unadjusted value that has been measured, whether it is a teenagers time in the mile run, an adult’s weight or Telecommunications firm’s average survey score on a seven-point scale on the “Customer Insight” dimension.
Taken alone, raw scores are not very useful or informative for anyone other than an expert. In other words, raw scores usually cannot answer the question, “Is that good or bad?”
This is why percentiles should be used for comparison, they provide context. In the case of the MRI they allow companies to compare themselves to the most customer centric companies in the world.