The SFUSD assignment process

You start by filling out an application where you rank-order up to 7 school choices. There are (almost) no restrictions on the schools, they can be anywhere within the district (for reference, San Francisco covers an area of 7x7 square miles, with famously uneven terrain). There are only two magnet schools with an entrance examination, so applying to these works differently. I will leave them out for the purposes of this discussion.

In addition to the 7 school choices, you also fill out the following 4 "diversity indicators" on the application:

1. HL -- Does the student speak something other than English at home
2. AAS -- Academic achievment status
3. SES -- Socio-economic status (e.g. student qualifies for free or reduced lunch)
4. EP -- Extreme poverty status (e.g. living in public housing)

For middle school or highschool applicants, there is an additional "diversity indicator" which is the API scores of the previously attended school.

The diversity indicators are binary in nature. So each student essentially is tagged with a 4 or 5 long bit-vector.

Schools are of two-kinds:

• Attendance-area -- applicants who live within the "attendance area" for that school are considered first, then applicants outside "attendance area" are considered after
• City-wide -- no preferrential treatment is given to applicants to that school based on location in the city, the "attendance area" is the entire city
  

On the day of the lottery, the algorithm does the following for every school individually:

1. Pre-assign siblings of an already-admitted student to the same school if that is among their choices; pre-assign special needs students to their top-choice.
2. Compute a preliminary "diversity index" on the basis of these pre-assignments.
3. For all students in the school's attendance area:
3a. Tentatively add her to the school, compute the new tentative "diversity index" including that student.
3b. Pick the student who contributes to the highest tentative "diversity index", give her the spot.
3c. If multiple students qualify in 3b, pick the student with the higher preference for that school on the application. If the preferences are also equal, pick randomly.
3d. Keep doing this until no student in the attendance area contribute positively to the tentative "diversity index"; at that point, repeat for BOTH attendance and non-attendance area students, and continue even if the diversity score is being brought down (pick the least negative one in that case). If there is a tie, attendance-area kids break ties.
3e. Repeat until all spots at that school are filled.

At the end, a student may be assigned to multiple schools. Assign the student to their top-choice, and repeat the steps 2-3e above to fill-in the openings.

The "diversity index" is a formula that's intended to maximize diversity at all schools, that is to say, make sure that the students who attend come from as many diverse backgrounds as possible.

If a student ends up with no school assignment, the district assigns them to some other school, close to their home, using an algorithm that is not described anywhere. In local parlance, this is called going "0/7".

A 0/7 student who wishes to continue applying for a different spot with SFUSD can now go through the "waiting-list" process, by expressing preference to a set of 8 additional schools. The assignment process is similar (diversity index-based), though more complex in some ways, and goes on until the first day of class. Some of these students get no assignments as well, that's called going 0/15.

The district advertises the following statistic about admission rates for the year 2009:

• 78% of K-12 applicants received one of their choices.
• 61% of K-12 applicants received their first choice.

Both of these statistics include siblings and special needs assignments (which do not go through the lottery -- they are pre-assigned by default). The district does not publish the aggregate admission statistics excluding siblings. Anecdotal evidence suggests that it is around 50-60% (that is 50-60% of non-sibling non-special needs applicants receive one of their choices), but that is not an official or verified number. The siblings numbers are available for a few select schools (which I quote below), but not in aggregate.

Some schools (generally, the ones with higher API scores) receive far more applications than they have seats, for example:

• Clarendon has 66 spots per year, of which 11 are siblings, and 55 for the general pool. They received 1128 applications.
• Rooftop has 66 spots, 19 siblings, and received 1086 applications.
• West Portal has 66 spots, 17 siblings, and received 986 applications.

The current system is sometimes described as "total choice", it has no provisions against congestion. Although, technically speaking, some schools have "attendance area zones" which theoretically should limit the number of students who apply from outside the zone, in reality that doesn't work. The reason is that many San Francisco neighborhoods are fairly uniform across the diversity criteria. As such, unless you are somehow "different enough" from other people in your neighborhood, you won't get any boost in the lottery, on the contrary. This is known, and for that reason, lots of non-attendance-area kids apply anyway. This creates congested situations like the 3 schools above (and many others) which end up having very unfavorable odds of getting in.

Legal resources about SFUSD

Some resources regarding the legal history of the SFUSD, in particular about some of the landmark lawsuits that shaped SFUSD's current student assignment process:

COURT-MANDATED EDUCATION REFORM: THE SAN FRANCISCO EXPERIENCE AND THE SHAPING OF EDUCATIONAL POLICY AFTER SEATTLE-LOUISVILLE AND HO V. SFUSD

"This Article reflects back on the San Francisco Consent Decree two years after its termination. Informed by the findings and conclusions of our systematic monitoring over a nine-year period, it seeks to reassess both the efficacy of race-conscious reform strategies and the value of court supervision itself as vehicles for change in education settings."

Goodwin Liu has written a lot of articles, in particular another on "Seattle vs. Louisvile". You can see more articles like that on his web page.

Gary Orfield has also written extensively on the subject, see more on the Civil Rights Project.

Strategic plan

A writer on the mailing list posted a nicely structured strategic plan for how to move forward on these issues.

If you think you can help with any of these, please leave a comment, or write to the mailing list indicating which item you'd like to work on, or just to bounce ideas. Better yet, just do it!

Short Term Plan (this month)

1. Increase membership of the group. Reach out to as many parents as possible. Diversity is key, families from many different backgrounds. Consider inviting 5 friends of family members to join the discussion and mailing list.
   
2. Get to know each other. Setup informal meetings periodically, setup polls to learn about where we live, what we care about.
   
3. Track action items and try to make progress on them.
   

Immediate Term Plan (1-3 months)

1. Meet with BOE members. Find out what their positions and where they stand with respect to the SFUSD strategic plan, achievment, proximity, etc. Just as important, get them to know us. Dispel perceptions of racism or exclusivity in the desire for proximity.
   
2. Learn more about family flight to the suburbs, other relevant demographic data, through the mailing list and this blog. Setup some polls.
   
3. Talk to teachers and teacher unions. What are their needs/opinions on this.
   
4. Involve the local media: newspapers, blogs, mailing lists, YouTube, etc.
   
5. Learn about other school districts and how they do it. What can we adopt/avoid?
   
6. Get other support: environmental groups, pediatricians (for childhood obesity, etc.)

Intermediate Term Plan (3-6 months)

1. Reach out to Board of Supervisors, mayor, other political groups.
   
2. Learn about 2010 BOE elections: fundraising, canvassing, etc. Maybe MoveOn.org?
   
3. Get someone elected: would it be realistic to have a BOE candidate from this group?
   

Long Term (6-12 months)

1. Improve all schools in SFUSD: the holy grail, this ultimately solves all problems.
2. Educate voters about the BOE

Polling ideas

Some readers suggested useful polls that we could gather in order to learn more about public school challenges and, specifically, how it plays into student assignment and families leaving the city.

1. Poll families about applying to public school vs. private.

2. Poll families about leaving the city after X years.

3. Poll students that leave SFUSD for some other district and/or private school.

4. Poll mothers clubs, such as Burlingame Mothers or Golden Gate Mothers Club to get their perspectives on public vs. private, staying vs. leaving the city.

Any other ideas? Please leave comments with additional ideas, informal poll results, or contact the blog authors if you'd like to run such a poll.

Welcome to San Francisco

The current San Francisco Student Assignment System could use some improvement. We're in luck! The San Francisco Unified School District is working on redesigning it!

I've decided to try and help out. On my first post, I'm going to share some of the resources I've found regarding the redesign:

• SFUSD page about the Student Assignment Redesign.
• SFUSD technical description of the current Student Assignment Process.
• SF K files posted a Hot Topic on the Student Assignment Redesign.
• The Parents for Public Schools of San Francisco website.
• The mysterious "attendance area" map is found on p41 of the SFUSD Enrollment Guide.
• A Google Map showing greatschools.net rankings of our SFUSD public kindergardens.
• Finally greatschools.net has gather statistics on public and private schools.
  

Finally, here are some things you may want to know about the assignment process, as it pertains to kindergarden:

• Each student has a Diversity Profile which consists of 4 binary digits (1 of 16 profiles). The digits are:

1. English as a primary language
2. Attended Kindergarden
3. Socioeconomic status
4. Extreme Poverty
   

• Each school is attempting to maximize diversity by aiming for 50% ones and 50% zeros for each Diversity Profile digit. They compute a Computed Diversity Index which is equal to the sum of percentage of 1's squared, plus the percentage of 0's squared for each binary digit.

• Each school has an initial Computed Diversity Index based on some students that are pre-assigned with sibling preferences and special program needs.

• Students are allowed to choose up to 7 schools on their application, ranked in order by preference.

• Schools fill empty seats from those who applied in the school's attendance area as long as their exists an applicant which improves the Computed Diversity Index.
  

• They use a greedy algorithm to fill the remaining seats at each school. To fill the next seat at a school - they determine which applicant will improve the Computed Diversity Index the most using attendance area, then preference rank, then randomness to break ties.

• At this stage, a student may have been "assigned" to multiple schools. They use the student's preference to determine which school the student is assigned to. This may open up seats at the students less preferred schools. If so, they repeat the prior step to fill those remaining seats.

• Once all of the empty seats are filled at all of the schools - some students may be left unassigned to any of their choices. The administrators try to pick a nearby school for them using some method that I could not find documentation for.