# How Niche Calculates Survey Scores for Private School Rankings

Note: The explanation below is for the Niche Best Private High Schools ranking, but the same method is used for other Niche Grades/Rankings. The specific mean values and weight percentages specified below vary by Grade/Ranking.

Niche Survey Scores are calculated on a 1-5 scale based on millions of reviews from students and parents. To account for a wide range of respondent counts and low respondent counts at some schools, our Survey Score ranking factor is calculated using a Bayesian method. This is a method that has been used by other rating/review services like Google, Amazon, and IMDB.  What this generally means is that each school starts out at the mean Survey Score across all schools – in this case 4.09 out of 5. Then as we get more responses for each school we have more statistical confidence pulling that school’s Survey Score away from the mean of 4.09 and toward that individual school’s mean score.

For example, a school with four reviews and a mean of 5 will get a score closer to 4.09 than a school with 20 reviews and a mean of 5. Similarly, a school with 50 reviews and a mean of 4.5 would ultimately have a higher score than a school with four reviews and a mean of 5. The same is true on the negative side. A school with three reviews and a mean of 1 will score higher (closer to 4.09) than a school with 30 reviews and a mean of 2.

Two other important things to note:

1. Survey Score only accounts for 10% of the weight in the Best Private High Schools ranking algorithm (that percentage is different for other rankings). We believe it’s important to factor in the opinions of students and parents but we also want to make sure we’re using a diversity of factors to determine the Overall Niche Grade/Ranking for a school.
2. The Survey Score (out of 5) value you see displayed as a “Ranking Factor” for a particular school is the school’s raw score, not it’s calculated score using the method above.

Where Our Data Comes From

Niche uses the most recently available data from the U.S. Department of Education as the basis for most statistical factors used in rankings. For private schools in particular, we also collect data directly from schools via our school data update form. If you work for a school and would like to update your data, please contact us. Our student-driven factors have also been updated based on millions of reviews and datapoints submitted by millions of Niche users over the last year. Learn more about where our data comes from.

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