Postsecondary Graduation Rate

The graduation rate is the percent of students who complete their degrees at institutions within “150% of normal time,” meaning three years for a two-year degree or six years for a four-year degree. Since 2011, graduation rates at local four-year institutions have remained steady, while graduation rates at local two-year institutions have increased.

For comparability, we limit the data to first-time, full-time students. Students are excluded from the calculations if they leave due to suffering a serious injury, enlisting in the military, or joining the foreign service of the government or an official church mission.

Degree Completions

Degree completions are the number of degrees conferred in a given year. Since 2008, the number of degree completions has increased at both two-year and four-year institutions.

This metric tracks the number of degrees conferred by institutions rather than the number of students who receive degrees. Since some students earn more than one degree, the number of graduates is lower than the total number of degrees.

Net Price

Net price is the total cost of attendance minus the average amount of financial aid that a student receives. Since 2009, the net price of local 4-year institutions has trended upwards, while the net cost of 2-year institutions has not.

The total cost of attendance includes tuition, fees, books, and the average cost of room and board. Financial aid includes both government aid from federal, state, or local government as well as institutional aid in the form of grants and scholarships.

 

Natural Breaks Algorithm

For each indicator, Greater Louisville Project assigns cities into one of three groups (high-performing, middle-of-the-pack, and low-performing) based on how they compare to other cities. The assignment is based on how cities naturally cluster on that indicator. Sometimes, the differences between cities are very small, and the difference between a city ranked 5th and 6th could simply be a matter of the sampling error that arises from using survey data. Thus, rather than always make a division that declares the top 5 to be the top tier, we use a natural breaks algorithm to look for a cluster of cities that is outperforming the rest, a cluster that is about average, and a cluster that is lagging. This clustering gives us a better indication of where Louisville is thriving and where Louisville has room to learn from cities that are doing better.

Z-Scores

Z-scores (or standardization) is a way to combine data with different units of measurement into a single index. The z-score is a measure of how far away a city (or census tract, etc.) is from the average city. In order to be comparable across different units of measurement, the z-score is the distance from the mean measured in standard deviations (e.g. if Louisville has a z-score of 1 it means Louisville is 1 standard deviation above the mean of its peer cities).

Data from the Robert Wood Johnson Foundation's County Health Rankings use z-scores and all z-scores are relative to the mean of Louisville's peer cities. (On the County Health Rankings site z-scores are relative to all the counties in each state - thus z-scores reported by GLP will be different, because we are using a different reference group). The Greater Louisville Project also uses z-scores in our multidimensional poverty index, which compares each census tract to the mean of all census tracts in Louisville.