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This tutorial has been created to help you understand how and why the state applies the confidence interval to determine whether a school met the AYP target. Since the accuracy of measures of student performance depend on the number of students participating in the assessments (the more students; the more accurate), the state uses a statistical test to take into account the number of students participating. The relationship is shown in the following two graphs.

The first graph shows the Reading 2007 AMO with confidence intervals.

The second graph shows the Mathematics 2007 AMO with confidence intervals. The red horizontal lines in both graphs represents the 2007 annual measurable objective (AMO) for a school that has grades 3, 4, and 5.

In compliance with NCLB, the AMO target increases each year toward the goal of 100% in 2014. So your school's AMO this year will be different than the AMO shown in this tutorial. Your confidence intervals will also be different whenever your AMO is different. The higher the AMO, the smaller the confidence intervals.

Looking at the two graphs, we can see that the X-axis represents groups of different sizes for the number of students participating in the assessment. The Y-axis represents the percent of students scoring at the proficient level. The blue lines represent the confidence intervals for each group size. You can see that the more students you have in a group, the smaller the blue line (the confidence interval).

Since we are only interested in whether a school met the AMO and not if they exceeded it, we focus on whether the score is below the blue line, which is outside the confidence interval. Scores falling on the blue line are statistically equal to the AMO. Scores below the blue line are statistically, significantly less than the AMO and, therefore, school performance does not meet the AMO target.