Wednesday, February 2, 2011

Public Elementary School Sibling Counts?

I just read below in a comments section that Miraloma has 29 incoming siblings for next year. That number seems incredibly high to me, considering there are only 3 kindergarten classes (and I now have even less hope of my son getting in there, but I digress...).

However, when I found that out it got me thinking that perhaps other people know the sibling counts at other schools. It could certainly make a difference for those who are still making lists. If half a school's spots are taken by siblings and you still have to factor in CTIP 1 applications... well, you get the idea. But, if a school has a small number of incoming siblings, that would be a good place to check out.

So, if you're in the know, post public school sibling counts here.

PS- Jefferson's principal told me she estimated 10 incoming siblings. Could that be right? So much lower than Miraloma and in a bigger school? Can anyone at Jefferson confirm this?

24 comments:

  1. The general rule of thumb for sibling count is usually between a quarter and a third. Then you take in Pre-K if applicable, and CTIP1 and, well ... you get the picture. I will ask at Alamo and post it here next week.

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  2. I heard the same number at a Miraloma your: 29 siblings (20 boys and 9 girls).

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  3. At Alvarado today the principal said he anticipates 50% of the spots will be taken by siblings. (N.B. They have 4 K classes - 2 GE and 2 SI)

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  4. Even more reason why the Dense-Population Tie breaker should be factored in AFTER siblings, Pre-K and CTIP1s are accounted for.

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  5. Miraloma has so many more boys than girls - if that number is true re: siblings (20 boys, 9 girls) that is crazy! This year it is only about 1/3 girls. They do not take gender into account in the lottery process.

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  6. Here is my back of the envelope calculation. Mathematician and statistician please correct me.

    1. US fertility rate is 2.1. That means the ratio of first child and younger children will be 1 : 1.1. That mean on average 50%+ seat will be taken by younger sibling.

    2. It does not affect to your school assignment chance. 50% less appliants will be competing for 50% less seat. Each school's seat will be reduced by the same proportion.

    Assumptions:
    - The old/young ratio should be adjust up to account for women with no child.
    - San Francisco fertility rate is same as national overall.
    - people stick to older sibling's school. (not move out of the city, have the older one in 'bad' school but try to put hte younger one in 'good' school, etc).

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  7. 12:02 PM
    It's too bad they don't consider gender as part of the mix. My daughter was part of a class of 1/3 girls at Miraloma recently and it definitely affected the balance of things (I also have a son, and speak from experience.)

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  9. 4:53 PM:

    Actually, it doen't matter about birth spacing, just total sibling number. It's cumulative effect of all families in the school, so Tung is correct.

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  10. Tung speaks with forked tongue.

    If you've got one sibling per family that doesn't amount down to 50% a year. Dude?

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  11. Anonymous said...

    4:53 PM:

    You are partly right. However you are also looking at differenet grade level all of whom can have younger sibling. So it goes like

    12% of 2 grade above have sibling coming in.

    n% of 3 grade above have sibling coming in.

    m% of 4 grade above have sibling coming in.

    Adding them up and you should get my number. That's my hunch.

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  12. They already have one for idiots so why not sexes?

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  13. Well, here's some historical data from a few years ago, and only a very few schools reached the 50% sibling threshold.

    http://portal.sfusd.edu/data/EPC/Siblings_Capacity_March%2017.pdf

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  14. Hi Tung,

    Loosely speaking, if each student had one sibling, half the students would already be the younger sibling. So I would cut your projection in half.

    I have never heard of a 50% sibling rate except as an anomalous event.

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  15. Don,

    You're wrong on this one. Tung is right.

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  16. I'm in the Grattan attendance area. My friend's son is in first grade there and there are six kids in his class alone with siblings entering K next year. That's just one first grade class out of three, not the mention the rest of the school, plus the CDC pre-K, plus CTIP1. I'm worried. But, I don't have the full count of expected siblings for that school. I'd also be curious to hear how many CDC kids who attend live in the attendance area. Are schools sharing that number?

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  17. Tung is right.

    Of course, there are assumptions. Assume each family has two kids, and people always stick to the older sibling's school, then when you look at the whole school, 50% of the kids are the younger one of the siblings, and 50% are the older one.

    With the above assumption "people stick to older sibling's school", those 50% who are the younger sibling would have entered the school with sibling preference. Very simple logic.

    Of course, in real world, that's not the case. Some siblings go to different schools. People move. Sometimes the gap between siblings is larger than 5 years (or 8 years for K-8). So the real % should adjust, and less than the 50% in concept. It is usually somewhere between 30% to 40% with occasional peak.

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  18. Why not look at actual DATA?

    Here's a sampling of sibling spots for some schools for the 2010-2011 School Year:

    There are numerous instances of an almost 50% sibling rate.

    ROOFTOP ALT 26
    CLARENDON ALT 17
    LAWTON ALT K GE 32
    WEST PORTAL ES 13
    LILIENTHAL ALT K GE 25
    GRATTAN ES K GE 19
    MIRALOMA ES K GE 27
    ALAMO ES K GE 29
    DIANNE FEINSTEIN K 34
    ARGONNE YR K GE 27
    SUNSET ES K GE 31
    FONG YU ALT K CN 31
    ULLOA ES K GE 26
    ALVARADO ES K SN 8
    CLARENDON ALT K JB 28
    WEST PORTAL ES K CN 5
    STEVENSON ES K GE 28
    PEABODY ES K GE 12
    SHERMAN ES K GE 16
    JEFFERSON ES K GE 20

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  20. My daughter is at the Grattan CDC and we live in the area and have applied for Grattan for K next year.

    I don't have an exact number but the CDC is not currently heavily populated with kids from the area. I'd say less than half, possibly even a third of the kids are from the area. So maybe about 13 kids are local?

    But the CDC mixes ages and not all of those kids are moving up to K next year. I'd think it's less than 10 kids who will be moving from the CDC to K at Grattan next year. I'm thinking hard about the kids who are my daughter's age at the CDC and most of them aren't from the area.

    However, that's changing as the new tiebreaker rules go into effect and parents locally are angling to get their kids into Grattan for K through the CDC.

    The CDC is great, btw. They completely refurbished the space over the summer and both teachers are young, very bright and very engaged with the kids. They also have a lot of in-class support, and it does have a strong emphasis on pre-literacy to prep kids for K.

    My very rough guess for Grattan would be about 18 siblings coming in, and about 7 to 10 from the CDC. So 25 to 28 spots out of the three K classes will be taken by sibs and Pre-K? Does that sound about right?

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  21. These are the #s that the principal of CIS @ DeAvila gave during a tour: 66 K spots, 44 of those are reserved for Cantonese-only and bilingual kids in round one but will be released to everybody after that, if they don't fill up (which they haven't in the past). There are 16 siblings. I guess, the count of siblings is still relatively low (as opposed to K-8 schools such as Alice Fong Yu), since the school only goes from K-3 right now, with one additional grade added each year, so it's still pretty small.

    Don't know if the siblings will be tested for language [there are still tours on 02/09 and 02/15, if you want to go by there and ask... you can call Ms. Janis at (415) 241-6325 to sign up for one of the tours] and if that'll result in more English-only family slots being offered in round 1.

    Good luck to everybody!

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  22. I have heard that Clarendon Second Community (GE) will have 20 open K spots next year. That would mean they are expecting about 24 siblings.

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  23. In our family's four years at Fairmount, it has always had equal numbers of girls and boys in each kinder class. So, I have to believe gender is factored in.

    Last year, we had a big sibling class. I think 21 of 60. This year is substantial but I don't think it is that big.

    At least for the current kinder class, that includes my daughter, Spanish language siblings definitely outnumbered English language sibs. Only 2 of the English-only kids in my daughter's class (total of 22), one being my daughter, had an older sibling.

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  24. I've done some further informal polling at Grattan and there are fewer kids moving directly up from the CDC to Kindergarten there than I thought.

    Several parents who would like to have their kids go to Grattan for K, had lost their local area status when the district redrew the boundaries.

    I think there will be less than 10 kids moving up from the CDC with local area status. Probably closer to 7 or 8.

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