How School Rankings Are Misleading U.S. Home Buyers

There are many things that parents look into when buying a new home, and at the top of this laundry list of criteria are the schools. As parents start to research schools, they will almost certainly find a school rankings website, the biggest of which is But school rankings websites can mislead home buyers to think they need to spend more money on a home, have longer commutes, and very little diversity in order to send their children to a good school. School rankings websites are missing the mark, and SchoolSparrow believes it has found a better way to rank schools. 


The Source

U.S. Home Buyers often turn to websites such as, Zillow, Redfin or when looking for a property. These websites have a data feed from GreatSchools which assigns a ranking (1-10) to schools in close proximity to properties on these websites. The criteria that GreatSchools uses to rank schools are “student access to advanced courses, student progress information, and equity data to help parents see whether or not all students are being served similarly”. However, a closer look at their methodology reveals that a large percentage of the criteria they use to rank schools is test score data, and they use the state average test score as the benchmark by which they interpret the test score data.

The Problem

The major problem with GreatSchools and other similar school ranking systems, is that research has shown that the biggest influencer of test scores at a school is parent income, not the quality of the school itself.  Research suggests that parent income is 80% of the reason test scores are what they are at any given school. So, without parent income as part of the equation, school rankings are simply comparing parent incomes at different schools.

This has a dual effect of:

 a) giving poor marks to schools with low parent income, even if a  school is far exceeding the expected test scores given the parent income at the school, and

 b) the state average test score is too low a bar for schools in privileged areas, resulting in high marks for undeserving schools. 

For example, the state average in Illinois is about 37% of kids meet or exceed the Reading/Language Arts portion of the MAP testing, and the average income in Illinois is about $67,000 a year.  If a majority of families in that school district make 2 or 3 times that amount, do you think 37% is an appropriate bar by which to measure school performance?

In order to combat this problem, SchoolSparrow has used data science to develop a ranking system that normalizes for parent income, effectively raising the bar for privileged schools, and lowering the bar for schools in economically challenged areas.

School Ranking Examples

Let’s take a look at some examples of school rankings that GreatSchools has assigned in order to illustrate this problem.

The first school we want to take a look at is Haugan Elementary in Chicago. Parents at this school are in a lower income bracket, and this school has an expected test score of 20.80, when adjusted for parent income. But the students at this school outperform expectations, scoring a 32.0 on the reading/language arts section of the MAP testing. When taking a closer look at this particular school, you can see that 97% of students at Haugan receive free lunch. This means that parents of Haugan students make a below average income, yet the students are exceeding expectations by over 50%. 

On GreatSchools, this school scores a grade of a 5/10, and says “this school may still have achievement gaps”. The reality of this is that this school is significantly exceeding test score expectations based on parent income.

On SchoolSparrow, Haugan Elementary scores an A grade because our ranking system is normalized for parent income.

Haugan Elementary. Image:

Let’s take a look at a school that ranks 8/10 on GreatSchools. This school is William Mitchell Elementary School in Needham, MA, a high income suburb of Boston. This is a school that has a student population that is 82% white, and only 1% of students receive free lunch. This is a school that has an expected test score of 75.72, but students are only achieving an average of 73.0 on their tests. Because of this, this school gets a grade of C- on SchoolSparrow. This school is falling below expectations, yet is still rated with a high mark on GreatSchools as a school whose students are performing well above the state average. 

William Mitchell Elementary. Image:

GreatSchools ranking system is flawed, as it favors predominantly white schools with parents who bring in a higher income. A “good school” is not just a school that achieves high test scores. At SchoolSparrow, we believe a more fair, equitable ranking system is one that identifies the extent to which a school exceeds expectations at any given parent income level. A good school should be categorized as a school in which students from all backgrounds can achieve a score higher than is expected based on parent income. These are the schools that are doing a great job of educating students. 

How Does This Mislead Home Buyers

The problem with GreatSchools is that it inadvertently exacerbates the segregation of our nation’s schools. Schools that are 9’s and 10’s are often located in privileged, predominantly white neighborhoods with expensive homes that lower income families cannot afford. At the same time, those families that are targeting high scoring schools are overlooking schools with socio-economic diversity, unaware that the lower scores at these schools are simply a reflection of that diversity and vibrancy, not that the school is “bad”.

Greatschools does nothing to help educate parents on this fact, and as a result, families are being pushed to the most privileged areas with expensive real estate, often in the suburbs with long commutes, less time with their family, and little to no diversity, all in the name of chasing ‘the best’ schools.

SchoolSparrow aims to educate parents on the impact of parent incomes, and provide a more equitable ranking system that elevates schools with socio-economic diversity, and reveals to parents hidden gems in more affordable neighborhoods. These hidden gems are located closer to the urban core with shorter commutes, leading to more time with family and more diversity.

In reality, there are great schools all over, and you do not have to live in the most expensive part of a city in order to find the best schools.

To illustrate an example of how GreatSchools ranking system is misleading home buyers. Imagine someone is looking for a home in Boston. If they were to go to GreatSchools, this is the map they would see.


From this map, it appears that “good schools” are very limited in the Boston city limits, as there are only 6 schools rated above a 5. Given Boston’s lottery system and no guarantee that your child will get into one of these 6 “good” schools, this map might lead a homebuyer to think the city of Boston is not an option if they want their child to go to a good school. The buyer is caught in the trap of finding a suburb they can afford, facing long commutes, less time with their family, and little diversity. 

But in reality, when adjusted for parent income, there are many schools in Boston proper that are overachieving. 

An example of one of these schools is Joseph J. Hurley, which is rated as a 5 on this map from GreatSchools. On SchoolSparrow, Hurley scores a B+ which indicates this school is outperforming expectations given the average parent income level at the school. Joseph J. Hurley has a diversity score of 15, and 56% of students get free lunch, indicating this school has both cultural and economic diversity. Based on parent income, Hurley’s expected test scores are 34.49. The actual average test score at the school is a 52.0, which is outstanding. On SchoolSparrow, Hurley is one of the best schools in the entire Boston region, including the suburbs, yet parents are overlooking Hurley because of a poor GreatSchools score.

Joseph J. Hurley School. Image:

This is a quality school that is in Boston proper with shorter commute times and more affordable homes, yet you would never know from looking at the rankings on GreatSchools. 

At SchoolSparrow, we adjust for parent income, and this allows homebuyers to identify schools that they would otherwise overlook as possible candidates for their kids. 


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