Niche Most Drug-Free Campus Ranking Methodology

The Most Drug-Free Campus ranking provides a comprehensive assessment of the drug and alcohol use at traditional four-year colleges and universities in the United States. It uses data sourced from various government and public data sets, Niche’s own proprietary data, and 297,663 opinion-based survey responses about drug and alcohol safety from 82,253 current students and recent alumni.

A high ranking in Drug Safety generally indicates that:

  • Students report that drug and alcohol usage is very low on campus and does not play a role in student life;
  • Students report that there is little or no peer pressure to use drugs or alcohol and that underage drinking is not prevalent in the campus community;
  • The campus reports a low number of drug and alcohol related arrests and referrals.

Colleges Assessed by this Ranking

At the time of calculation, our database contained records for 2,245 public and private, traditional four-year colleges and universities across the United States. For the purposes of this ranking, a "traditional" college is considered to be any accredited, non-profit post-secondary institution that primarily offers four-year degree programs (as opposed to two-year or less). Some colleges were not included in this ranking if: (1) they were not located in one of the 50 U.S. states, Puerto Rico, or the District of Columbia; (2) they had fewer than 100 full-time undergraduate students; or (3) they had insufficient data (see below). The final ranking results in 1,359 colleges receiving a grade, with 1,177 of those also receiving a numerical ranking.


U.S. Department of Education

Factors Considered

FactorDescriptionSourceWeight
Student Survey Responses Student opinions about drug and alcohol safety at the college they currently or recently attend(ed). Includes 267,663 reviews and opinions from 82,253 unique students. Minimum 19 unique students required at each college. Niche users 75%
Drug-Related Arrests Rate of drug-related arrests on campus per 1,000 students, as reported by the college. U.S. Department of Education 10%
Alcohol-Related Arrests Rate of alcohol-related arrests on campus per 1,000 students, as reported by the college. U.S. Department of Education 5%
Alcohol-Related Referrals Rate of alcohol-related referrals on campus per 1,000 students, as reported by the college. U.S. Department of Education 5%
Drug-Related Referrals Rate of drug-related referrals on campus per 1,000 students, as reported by the college. U.S. Department of Education 5%

Statistics obtained from the U.S. Department of Education represent the most recent data available, usually from either 2012–2013 or 2013–2014, as self-reported by the colleges.

Computation

The process used to compute this ranking was as follows:

  1. First, we carefully selected the factors listed above to represent a healthy balance between statistical rigor and practical relevance in the ranking.
  2. Next, we evaluated the data for each factor to ensure that it provided value for the ranking. (The factor needed to help distinguish colleges from each other and accurately represent each college.) Because there are different factor types, we processed them differently:
    • Factors built from student-submitted survey responses were individually analyzed to determine a required minimum number of responses. After this, responses were aggregated. We logically have a higher degree of confidence in the aggregated score for colleges with more responses, so a Bayesian method was applied to reflect this confidence.
    • Factors built from factual information were inspected for bad data, including outliers or inaccurate values. Where applicable, this data was either adjusted or completely excluded depending on the specific data.
  3. After each factor was processed, we produced a standardized score (called a z-score) for each factor at each college. This score evaluates distance from the average using standard deviations and allows each college's score to be compared against others in a statistically sound manner.
  4. With clean and comparable data, we then assigned weights for each factor. The goal of the weighting process was to ensure that no one factor could have a dramatic positive or negative impact on a particular college's final score and that each college's final score was a fair representation of the college's performance. Weights were carefully determined by analyzing:
    • How different weights impacted the distribution of ranked colleges;
    • Niche student user preferences and industry research;
    • Each factor's contribution to our intended goal of the ranking described in the introduction above.
  5. After assigning weights, an overall score was calculated for each college by applying the assigned weights to each college's individual factor scores. This overall score was then assigned a new standardized score (again a z-score, as described in step 3). This is the final score for the ranking.
  6. With finalized scores, we then evaluated the completeness of the data for each individual college. Depending on how much data the college had, we might disqualify it from the numerical ranking or from the grading process. Here is how we distinguished these groups using the weights described in step 4:
    • Colleges missing the data for 50 percent or more of the factors (by weight) were completely excluded. They did not qualify for the numerical ranking or a grade. Note: This exclusion occurred before calculation of the final z-score.
    • Colleges that had all of the factors and more than 1,000 full-time undergraduate students were deemed eligible for both a grade and a numerical ranking. Colleges that did not have all of the factors or did not meet enrollment requirements were not included in the numerical ranking and received a grade only.
  7. Lastly, we created a numerical ranking and assigned grades (based on qualifications discussed in step 6). Here is how we produced these values:
    • The numerical ranking was created by ordering each college (when qualified) based on the final z-score discussed in step 5.
    • Grades were determined for each college (when qualified) by taking the ordered z-scores (which generally follow a normal distribution) and then assigning grades according to the process below.

Grading Process for This Ranking

While our ranking shows the Top 100 colleges, we use grades to provide the user some context to those rankings and also to provide insight into colleges that did not make the Top 100. It's important to focus on more than just the number in the ranking. Given the high number of colleges included in this ranking, there may not be a large gap between the 15th and 30th ranked colleges. In reality, both are exceptional colleges when compared to the total population of all colleges nationwide. Grades are assigned based on how each college performs compared to all other colleges included in the ranking by using the following distribution of grades and z-scores:

GradeFinal Z-ScoreCountDistribution
A+ 1.96 ≤  z 145 10.58%
A 1.28 ≤  z < 1.96 139 10.15%
A- 0.84 ≤  z < 1.28 99 7.23%
B+ >0.44 ≤  z < 0.84 102 7.45%
B 0.00 ≤  z < 0.44 158 11.53%
B- -0.44 ≤  z < 0 183 13.36%
C+ -0.84 ≤  z < -0.44 139 10.15%
C -1.28 ≤  z < -0.84 135 9.85%
C- -1.96 ≤  z < -1.28 170 12.41%
D+ -2.25 ≤  z < -1.96 42 3.07%
D -2.50 ≤  z < -2.25 21 1.53%
D- -2.50 > z 37 2.70%

Note that we intentionally did not assign a grade below D- to any colleges.

The Outcome

Of the 2,245 colleges analyzed, 1,359 received a grade, with 1,177 of those also receiving a numerical ranking. The top ranked college was Brigham Young University - Idaho, which along with second-ranked Brigham Young University in Provo, Utah, scored favorably in all factors and had a final score that was over 3.5 standard deviations from the mean. BYU completed its strong showing with BYU - Hawaii rounding out the Top 5.

It’s important to note that this ranking's distribution was less normal than many other Niche rankings, with many colleges scoring very highly and many scoring very poorly. Further, all alcohol and drug arrest/referral data is self reported by the colleges, and the statistics are impacted by a particular campuses policies towards drinking on campus, underage drinking, rule enforcement, and whether incidents are handled by campus or local police. Due to these considerations, we gave limited all of these factors to 25 percent of the weight, giving Student Survey scores 75 percent of the weight.

In addition to the BYU campuses above, we'd also like to point out that several colleges scored extremely well but did not qualify for the numerical ranking due to insufficient data or an undergraduate enrollment below the minimum 1,000 students. Thirty-four colleges still received an A+ grade for Drug Safety but no numerical ranking, including Grove City College, Corban University, Johnson University, Loma Linda University, and United States Naval Academy. With full data, these colleges may have ranked in the top 100.

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