How We Measure Change Over Time
As in previous editions, the Change Over Time arrows in Measuring Up 2008 compare each state’s current performance with its own previous performance in the 1990s. This year, however, a state’s Change Over Time is determined by its improvement or decline in performance on a key indicator in each performance category. The key indicators were selected because they are broad gauges for understanding state success in the performance areas. The key indicators are:
- Preparation: Percentage of 18- to 24-year-olds with a high school credential (1990 to 2006)
- Participation: Percentage of 18- to 24-year-olds enrolled in college (1991 to 2007)
- Affordability: Percentage of income (average of all income groups) needed to pay for college expenses at public four-year institutions (1999-2007)
- Completion: All degree completions per 100 students (1992-2007)
- Benefits: Percentage of 25- to 64-year-olds with a bachelor’s degree or higher (1990 to 2006)
States receive either an “up” or a “down” arrow in each performance area. An “up” arrow indicates that the state has increased or remained stable on the key indicator in the category, a “down” arrow indicates that the state has declined on the key indicator in the category. In addition, information about Change Over Time is presented graphically in greater detail on the second page of each state’s summary report card. The National Center does not establish benchmarks for improvement; however, the Change Over Time performance of the top states is depicted graphically on the second page of each state’s summary report card. Many states, but not all, have improved on these key indicators. Affordability is different from the other categories in that lower percentages indicate higher performance.