Health outcome metrics 10th among list of 15 peer cities, says ‘Building A Healthier Louisville’ report
October 7, 2013Recent Kaiser Report affirms GLP Report highlighting the increased demand for primary care providers.
September 9, 2013As 55K Sunsets, Fight for Equity and Affordability in Postsecondary Education Continues
August 22, 2020Greater Louisville Project Releases 2019 Competitive City Report: The Flow of Community Investment
July 7, 2020See what Kentucky Youth Advocates Research Director, Amy Swann has to say about the 2020 Census
June 22, 2020See what Metro United Way Director of Engagement, Mandy Simpson has to say about the 2020 Census
June 22, 2020Partner Spotlight: Universal Woods CEO Paul Neumann on the benefits of employee higher ed and paying tuition up-front
March 19, 2020Some college, no degree: Getting Louisville’s adult learners across the finish line
February 10, 2020Guest Blog: Regan Hunt, Kentucky Voices for Health – Health Coverage for better Health Outcomes
December 2, 2013Natural 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.