Confidence intervals take into account the fact that the students tested in any particular year might not be representative of students in that school across the years. Confidence intervals control for this sampling error or variation across years by promoting schools or subgroups that come very close to achieving their performance goals, thus meeting their specific goal. In 2004, the United States Department of Education approved a 95% Confidence Interval (C.I.) in Pennsylvania for AYP performance calculations. A 95% C.I. can be used for meeting the state performance goal, while a 75% C.I. can be used for meeting the Safe Harbor target.

The Growth Model recognizes the efforts of schools and districts/LEAs whose students have not achieved proficiency but are on trajectories towards proficiency on future PSSA exams. The Growth Model will be calculated for Performance Indicators (i.e., the all student group and up to nine subgroups). Projected scores are calculated for all students - including students who are proficient. If a projected score cannot be calculated for a particular student, the student’s actual score is used. The Growth Model will be applied to an AYP Performance Indicator only if the indicator cohort has not met AYP performance by any of the existing goals or targets. Actual, not projected, PASA scores, PSSA-M scores, 3^rd grade scores, and 11^th grade scores are always used, as well as the scores for any students with insufficient data points to make a projection.