California Is Using National Standardized Testing
California has been administering nationally normed achievement tests since spring 1998. Such tests were ready and available, and they meet the state's own guidelines of using multiple measures to assess student academic achievement.
There are numerous off-the-shelf academic achievement tests, and in 1998, California contracted with Harcourt Brace to use the Stanford 9 test (also known as the SAT-9) for a four year period that has just ended. For the next period, the state will be administering a different nationally normed achievement test, the California Standards Test.
To read more about what Harcourt Brace, the publisher of the SAT-9 has to say about the test, link here.
What It Means to Be Nationally Normed
The SAT-9 is a nationally normed test. This
means that before the test was made available to the public, the publisher gave
the test to a random group of children across the nation and plotted their results on a bell
curve. This is what a bell curve looks like:
Harcourt Brace gave the SAT-9 test to about half a million children as their sample group prior to making the test public. The sample group took the test in 1995, and in 1996 Harcourt Brace made the SAT-9 available to the public.
When schoolchildren in California began taking the SAT-9 test in math and language arts/reading/spelling in spring of 1998, Harcourt Brace did not norm the test again or create a new bell curve.
Instead, when California schoolchildren took the SAT-9 their results are compared to the original 1995 sample group. Harcourt simply plotted a child's test results (the number of correct answers) on the old 1995 bell curve and then gave parents that information in the form of a "percentile ranking." This "percentile ranking" told parents and children where a child’s raw score (number of answers correct) fell on the bell curve that was created from the 1995 national sample group.
This means that to be above the 50th percentile in 1998, a child needs to get more correct answers on a test than the average child (50th percentile) answered correctly in 1995.
Thus, by improving group-wide academic achievement after the norming date of a "nationally normed" test, groups of children taking the test, e.g., all the school children in California, could find their average percentile rankings above the 50th percentile.