In reviewing some schools’ RTI plans, a standardized reading achievement test is used as a screening device. Students are put in Tiers I, II, or III reading intervention groups based on their percentile ranking on standardized tests. For example, if you’re in the 10th percentile or below, you go to Tier III, the 40th percentile or below you go to Tier II, and the 60th percentile or below you go to Tier I.

When you live in the world of standardized tests and percentile rankings, there is a normal distribution of scores that is beautifully displayed in the bell-shaped curve. Here, half the population is reading below average. That’s called a normal population or a normal distribution of scores. But if everybody was reading above average, eventually average would become below average and above average would become average, and below average would become really below average. In a normal distribution of scores, half the students in a school should score below average. That’s called normal. That doesn’t mean that we don’t give each and every student the help they need so that they’re reading, writing, and doing math at their very best. We want all students to achieve grade-level standards. It is an excellent goal, but at the same time, it’s an unrealistic goal.