How School Rankings Are Misleading U.S. Home Buyers

There are many factors for parents to consider when buying a new home. At the top of this laundry list of criteria are the schools. When parent start researching schools, they will almost certainly find a school rankings website, the biggest of which is But established 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 that serve a particular home. The criteria that GreatSchools uses to rank schools is found on their website:

“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. GreatSchools uses 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.  In fact, test scores at any given school are up to 80% determined by parent income and 20% other factors. 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 expectations, 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 a school make double that amount, is 37% an appropriate bar by which to measure school performance?

Using data science, SchoolSparrow has developed a ranking system that normalizes for parent income. Our ranking system effectively raises the bar for privileged schools, and lowers 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.

Haugan Elementary – an underrated hidden gem

Consider Haugan Elementary in Chicago, with 97% of it’s student qualifying for free lunch. 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. 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 its students are far exceeding expectations.

Haugan Elementary. Image:
William Mitchell Elementary – overrated?

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 school has a student population that is 82% white, and only 1% of students receive free lunch. Mitchell has an expected test score of 75.72, but students are only achieving an average of 73.0 on their tests. This school gets a grade of C- on SchoolSparrow. But because this school’s test scores are well above the state average, GreatSchools scores this school an 8/10.

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 identifying the extent to which a school exceeds expectations at any given parent income level creates a more fair, equitable ranking system. A school is doing something right when students achieve test scores higher than expected; 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, 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. 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. Our more equitable ranking system elevates schools with socio-economic diversity, and reveals to parents hidden gems in more affordable neighborhoods. These schools are often located closer to the urban core with shorter commutes, more affordable homes, and more diversity.

Moving to Boston?

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.


In Boston’s city limits there are only 6 schools that rate above a 5. But given Boston’s lottery system, there is no guarantee your kids will get into one of these 6 “good” schools. As a result, homebuyers might eliminate the city of Boston as an option due to the schools. Hello Suburbs. Hello long commutes, expensive real estate, and very little diversity.

But in reality, when parent income is accounted for, Boston proper has many overachieving schools. 

An example of one of these schools is Joseph J. Hurley, which has a 5 rating 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. 

View our list of 5 hidden gems in Boston proper.

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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