Kindergarten assignment: the sibling effect

I keep meaning to post this data, which I asked for ages ago and never seem to have on hand when someone asks me about the issue of including siblings in the statistics showing how many families receive their first choice. In enrolling for 2009-10, for example, 80 percent of families requesting a Kindergarten seat received their one of their choices, with 64 percent receiving their first choice (see highlights of 2009-10 enrollment here).

For years, people have complained that these two statistics are inflated because they include siblings, who receive preference at an older brother or sister’s school — and there is a difference, primarily in whether families get their first choice or no choice at all — but I don’t think it’s as significant as people think it is:

  • As I said above, 80 percent of all applicants to K in 2009-10 received one of their choices; and if applications submitted by younger siblings are excluded from this statistic, 74 percent receive one of their choices — a difference of six percentage points.
  • In looking at the number of 2009-10 K applicants who received their first choice, there’s a drop of 11 percentage points if younger siblings are excluded (from 64 percent to 53 percent). This isn’t particularly surprising or damning, considering that sibling preference only kicks in if you list the older sibling’s school as your first choice.
  • Finally, the number of families who get none of their choices increases about 6 percentage points if you exclude the applications of younger siblings from the statistic. In other words, about 20 percent of all families didn’t receive a choice in Round I last year; that figure increases to 26 percent if you exclude younger siblings.

Of the 947 families who did not receive any of their Round I choices last year, almost 800 listed one of these high demand schools as their first or second choice:

  • Alamo
  • Alice Fong Yu
  • Alvarado
  • Clarendon
  • Grattan
  • Lawton
  • Lilienthal
  • Miraloma
  • Rooftop
  • Sherman
  • West Portal

The way I interpret this data is that people are focusing a bit too much on how the statistics are developed and not enough on the choice patterns for high demand schools — I find the list above to be stunning. If you have your heart set on one or more of these schools for Kindergarten next year, you may have to settle in for the long haul, because a lot of other people have their hearts set on them too.


4 responses to “Kindergarten assignment: the sibling effect

  1. I’m actually very surprised that the non-sibling acceptance rate is 74%. I assumed that it was closer to 50%. From a PR perspective, the district should have this information out for the press release they do after Round I is over. This is really good news, and needs to be shared to curb the rumors, ideas and “feelings” of a lower acceptance rate.

    Those eleven schools are an interesting bunch, too. They’re fairly clustered geographically in the North and West. The lottery redesign indicated that more demand is expected in the southeast. It would also be interesting to know what the racial/ethnic breakdown is for those 800 and 947 families is. It probably just reflects the population of families that participate in the lottery.

  2. thanks, Sarah! I’ve edited the post to reflect that we’re talking about percentage points and not percentages.

  3. Thanks for posting this information Rachel. I’ve long suspected the data looks something like this, and I’m glad to have the information.

    However, I just wanted to clarify one thing in your post. The difference between 80% and 74% is 6 points, however that represents a 7.5% difference in likelihood of getting your choice.

    This statistical idea is more important when looking at those who got none of their choices. The difference is again 6 points (20% vs. 26%). However, this means that you are 30% more likely to not get one of your choices if you have no sibling preference.

    With that said, you are absolutely right to stress the importance of looking beyond the most popular schools.

  4. In any redesign of student assignments, these high demand schools, from Alamo to West Portal, could remain city-wide schools, without a single school attendence area or a multi-school zone. As city-wide schools, address fraud would not be an issue.