Common Lottery Algorithm

[Anonymous]

Anonymous wrote:I did, and my understanding is that is not the model we are using (the NYC/Bost model differs from the Denver model which differs from the New Orleans model.)

Explain this, if the ranking matters in that ranking a school higher gives you a better chance of getting in, is there not an incentive to put a "safety" higher on the list then?

NYC/Boston/Denver/New Orleans all use the same basic system with some slight differences.
It's run in a series of iterations, with assignments only being temporary at first, and reassignments done throughout the iterations.
This model means is "strategy-proof," meaning that because of its iterative nature, the best thing to do is to simply list your preferences.

[Anonymous]

If I ranked a school 4 and didn't get in to 1-3 the system basically reassigns my 4 to my number one spot, this is where the draw comes in to play. If it were he case that the ranking weights the algorithms decision, then there is plenty more strategy to this than DC is saying. And, even with an early draw i could be screwed, and I guarantee you they will deny that if you call the my schools hotline...

[Anonymous]

Anonymous wrote:I did, and my understanding is that is not the model we are using (the NYC/Bost model differs from the Denver model which differs from the New Orleans model.)

Explain this, if the ranking matters in that ranking a school higher gives you a better chance of getting in, is there not an incentive to put a "safety" higher on the list then?

You are making value judgements re: what constitutes "acceptable criteria for any particular family's choices" vs. "unacceptable criteria". For one family, the idea of having a better chance at admission, having a school identfied as where their child can go, and being able to plan around their child's attendance, getting to know the school, etc, can all be reasons for choosing a "safety" as #1 over a school that, when just comparing schools, they would be more excited about but they know that last year they admitted 2 students with no preferences so they don't want to waste their #1 choice. Who are you to decide that that family's need/desire for resolution with this - because, be very clear, they need to live with their choice and would be fools to choose a "safety" that they wouldn't be happy about their child attending because they will be knocked out for good from the lottery if they get into their #1 - who are you to say that isn't a valid choice for a family to make and that that is "gaming the system"?

Just as some families hold close proximity to their home as a key factor, or bilingual education as non-negotiable, some families are totally freaked out and dismayed by this whole application system in DC and just want to know they don't have to worry about it as well as knowing their child is in a school they're happy with (even if it's not their absolute favorite school in and of itself). There are people (only a few, but there are a few) who absolutely adore Mundo Verde but don't think they can make the transition to the new location work for their family. That is a big consideration, and each family's calculations of what amounts to their #1 choice are different.

Your value judgement on what a "true choice" is does not govern and should not govern every other's families' choices.

[Anonymous]

Anonymous wrote:If I ranked a school 4 and didn't get in to 1-3 the system basically reassigns my 4 to my number one spot, this is where the draw comes in to play. If it were he case that the ranking weights the algorithms decision, then there is plenty more strategy to this than DC is saying. And, even with an early draw i could be screwed, and I guarantee you they will deny that if you call the my schools hotline...

No, 4 remains 4 just like 1 remains 1, 2 remains 2, etc and so on.

[Anonymous]

Anonymous wrote:If I ranked a school 4 and didn't get in to 1-3 the system basically reassigns my 4 to my number one spot, this is where the draw comes in to play. If it were he case that the ranking weights the algorithms decision, then there is plenty more strategy to this than DC is saying. And, even with an early draw i could be screwed, and I guarantee you they will deny that if you call the my schools hotline...

Yes, your #4 becomes your #1 if you strike out at 1-3, but the fact that you didn't rank your #4 school as #1 in the first place makes someone who actually ranked it #1 more likely to get it once the computer is sorting among your preference group for that school. You do not look like a #1 choice just because you're waitlisted at your 1-3 by the time the computer is considering you for your #4 school as compared to others for whom it was always #1.

[Anonymous]

I am getting confused. I thought the algorithm doesn't weight the parents' ranking, but lots of people are saying now that it does.

[Anonymous]

Anonymous wrote:I am getting confused. I thought the algorithm doesn't weight the parents' ranking, but lots of people are saying now that it does.

A lot of people are saying a lot of things. What I will point out is, regardless of what the different perspectives here are, if you talk to the Common Lottery staff and staff at some of the participating schools, they all say that the parent's ranking DOES matter and can influence the results. No one, and I mean no one that I have talked to about this who's actually directly involved has said that the parent's ranking doesn't matter.

The specifics of how the algorithm works, where/when ranking comes into play... lots of opinions about that. But no one official in this has said that parent ranking doesn't influence the results, and some schools (including Mundo Verde on their admissions page of their official website) are saying ranking DOES matter. That is why this is considered "2-way matching", trying to match the people the schools are prioritizing with the people prioritizing that school.

[Anonymous]

Anonymous wrote:

Anonymous wrote:If I ranked a school 4 and didn't get in to 1-3 the system basically reassigns my 4 to my number one spot, this is where the draw comes in to play. If it were he case that the ranking weights the algorithms decision, then there is plenty more strategy to this than DC is saying. And, even with an early draw i could be screwed, and I guarantee you they will deny that if you call the my schools hotline...

Yes, your #4 becomes your #1 if you strike out at 1-3, but the fact that you didn't rank your #4 school as #1 in the first place makes someone who actually ranked it #1 more likely to get it once the computer is sorting among your preference group for that school. You do not look like a #1 choice just because you're waitlisted at your 1-3 by the time the computer is considering you for your #4 school as compared to others for whom it was always #1.

The only way you lose a spot during the deferred acceptance algorithm is if someone else has a higher weighted preference, not a lower numbered rank.

[Anonymous]

Anonymous wrote:I am getting confused. I thought the algorithm doesn't weight the parents' ranking, but lots of people are saying now that it does.

You thought right, and they thought wrong.

[Anonymous]

Anonymous wrote:

Anonymous wrote:I am getting confused. I thought the algorithm doesn't weight the parents' ranking, but lots of people are saying now that it does.

A lot of people are saying a lot of things. What I will point out is, regardless of what the different perspectives here are, if you talk to the Common Lottery staff and staff at some of the participating schools, they all say that the parent's ranking DOES matter and can influence the results. No one, and I mean no one that I have talked to about this who's actually directly involved has said that the parent's ranking doesn't matter.

The specifics of how the algorithm works, where/when ranking comes into play... lots of opinions about that. But no one official in this has said that parent ranking doesn't influence the results, and some schools (including Mundo Verde on their admissions page of their official website) are saying ranking DOES matter. That is why this is considered "2-way matching", trying to match the people the schools are prioritizing with the people prioritizing that school.

Not really. They are saying "Rank us #1 to increase your chances." If I rank Mundo Verde #3, and I get in to my 1 or 2 choice, then I am completely off the Mundo Verde list. I have lost any chance of attending the school. If I want to guarantee a CHANCE to get in any given school, I need to rank that school #1. So yes, ranking obviously matters. It matters a lot. However, it does not mean that ranking the school a school #1 adds a weight to my chances of getting in to that school.

[Anonymous]

Anonymous wrote:

Anonymous wrote:I am getting confused. I thought the algorithm doesn't weight the parents' ranking, but lots of people are saying now that it does.

You thought right, and they thought wrong.

Believe parent ranking doesn't matter at your own peril. Don't trust anonymous "experts" here. Get info directly from the source.

[Anonymous]

Anonymous wrote:

Anonymous wrote:I am getting confused. I thought the algorithm doesn't weight the parents' ranking, but lots of people are saying now that it does.

You thought right, and they thought wrong.

Ha, okay. Wishful thinking on some people's part that putting #1 is going to help. Thanks.

[Anonymous]

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:I am getting confused. I thought the algorithm doesn't weight the parents' ranking, but lots of people are saying now that it does.

A lot of people are saying a lot of things. What I will point out is, regardless of what the different perspectives here are, if you talk to the Common Lottery staff and staff at some of the participating schools, they all say that the parent's ranking DOES matter and can influence the results. No one, and I mean no one that I have talked to about this who's actually directly involved has said that the parent's ranking doesn't matter.

The specifics of how the algorithm works, where/when ranking comes into play... lots of opinions about that. But no one official in this has said that parent ranking doesn't influence the results, and some schools (including Mundo Verde on their admissions page of their official website) are saying ranking DOES matter. That is why this is considered "2-way matching", trying to match the people the schools are prioritizing with the people prioritizing that school.

Not really. They are saying "Rank us #1 to increase your chances." If I rank Mundo Verde #3, and I get in to my 1 or 2 choice, then I am completely off the Mundo Verde list. I have lost any chance of attending the school. If I want to guarantee a CHANCE to get in any given school, I need to rank that school #1. So yes, ranking obviously matters. It matters a lot. However, it does not mean that ranking the school a school #1 adds a weight to my chances of getting in to that school.

So let's be clear: you are saying that once students are grouped by preference, and the algorithm is filling slots for a highly popular school for the sibling preference group, you are saying once you're in that group, the child who ranked the school #4 has an equal chance of getting the slot as the child who ranked the school #1? Assume #4 has already not gotten into their 1-3 choice. That is what you are saying, correct, that it's either equal chances or random at that point?

[Anonymous]

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:I am getting confused. I thought the algorithm doesn't weight the parents' ranking, but lots of people are saying now that it does.

You thought right, and they thought wrong.

Ha, okay. Wishful thinking on some people's part that putting #1 is going to help. Thanks.

Right, because somehow your opinion on this is more legitimate than what actual authorities involved this year, in this lottery in this are saying... Ha, okay.

[Anonymous]

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:I am getting confused. I thought the algorithm doesn't weight the parents' ranking, but lots of people are saying now that it does.

A lot of people are saying a lot of things. What I will point out is, regardless of what the different perspectives here are, if you talk to the Common Lottery staff and staff at some of the participating schools, they all say that the parent's ranking DOES matter and can influence the results. No one, and I mean no one that I have talked to about this who's actually directly involved has said that the parent's ranking doesn't matter.

The specifics of how the algorithm works, where/when ranking comes into play... lots of opinions about that. But no one official in this has said that parent ranking doesn't influence the results, and some schools (including Mundo Verde on their admissions page of their official website) are saying ranking DOES matter. That is why this is considered "2-way matching", trying to match the people the schools are prioritizing with the people prioritizing that school.

Not really. They are saying "Rank us #1 to increase your chances." If I rank Mundo Verde #3, and I get in to my 1 or 2 choice, then I am completely off the Mundo Verde list. I have lost any chance of attending the school. If I want to guarantee a CHANCE to get in any given school, I need to rank that school #1. So yes, ranking obviously matters. It matters a lot. However, it does not mean that ranking the school a school #1 adds a weight to my chances of getting in to that school.

So let's be clear: you are saying that once students are grouped by preference, and the algorithm is filling slots for a highly popular school for the sibling preference group, you are saying once you're in that group, the child who ranked the school #4 has an equal chance of getting the slot as the child who ranked the school #1? Assume #4 has already not gotten into their 1-3 choice. That is what you are saying, correct, that it's either equal chances or random at that point?

Not pp, but yes I believe that the child who ranked it #4 and the child who ranked it #1 have an ALMOST equal chance. The ALMOST has to do with the random lottery number they were assigned. If the child who ranked it #4 has a better lottery number (and is in the same preference pool) they will get the seat. If the child who ranked it #1 has a better lottery number (and is in the same preference pool) then they will get the seat.

Again, to be clear this is all based on the assumption that the child who ranked MV as #4 was locked out of #s 1-3.