Because each year’s test includes different questions, it is likely that the questions are, on average, slightly easier or slightly more difficult than was the prior year’s test. To ensure that test scores are comparable given these slight year-to-year differences, a standard statistical process called equating is employed. Equating adjusts slightly the number of raw score points (., questions answered correctly) needed to achieve a certain scale score and performance standard, relative to the small difference in difficulty of the current year's test. For example, if the current year’s test is slightly easier than was the prior year test, the number of raw score points necessary to achieve a given performance standard will increase slightly. If the current year’s test is slightly harder than was the prior year test, the number of raw score points necessary to achieve a given performance standard will decrease slightly.