<p>Interesting discussion. Arabrab, why don’t you just pick a child, say Child 1, and assign her to the first school on her list that has an opening? Then pick Child 2, and assign him to the first school on his list that has an opening? And so forth? Then the students have no incentive not to put their true preferences on their lists.</p>
<p>I think it’s grossly unfair to have a matching system that requires students to manipulate their preference lists to succeed, because many students won’t have the inside knowledge to do it.</p>
<p>I don’t know if there is manipulation necessary. I’m not sure where that even came from. I’m just trying to get a sense of how likely it would be that a kid wouldn’t get a match at all, so we can start planning for private school.</p>
<p>“… why don’t you just pick a child, say Child 1, and assign her to the first school on her list that has an opening?”</p>
<p>Fang - But how do you identify “Child 1?” Alphabetical? (Perhaps that’s why Neil Young ended up in music.) Highest grades? (No pressure for Middle School grade inflation there I’m sure.) Closest to school? Oldest? Most years in District School System? Do you consider race? Disciplinary history? Teacher recommendations? GC recommendations? Does a child’s handicap come into play? Athletic ability? Musical talent?</p>
<p>There is another wild card here. I’ve known kids who didn’t get any match but who then got into good high schools that were better than those they would have gotten if they had filled all the spaces on their list. </p>
<p>It’s not as if the 8% don’t get into a school at all. They do. The info you need is where the SI kids who don’t get matched in the first round end up going. If they have options you’d prefer to your lowest choices, then you might be better off being forced into the second round then settling for a school you wouldn’t send him to anyway. </p>
<p>If private school is an option, I would NOT rank any school he wouldn’t choose over a private school WHERE HE IS LIKELY TO BE ADMITTED. If private school isn’t an option and he must go to public school, then fill them in.</p>
<p>Without beating the subject to death … other posters noted this earlier … it’s unlikely the assignment process is random. People H.A.T.E random. “Johnny and Billy live right next door to each other and have the same grades. And yet Johnny is going the the school around the corner, and Billy was assigned across town and has a 45-minute bus ride each way.” Well, that’s the essence of “random” … and it’s very unreasonableness is why it’s used so infrequently in human endeavors.</p>
<p>The same way arabrab says her system does it: randomly.</p>
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<p>It came from what arabrab said: that students should not write down their actual preferences. Instead, they should write down a different list, which is not the actual preference but which is likely to get them an outcome they prefer. I think it’s appalling to have a system that rewards students whose parents are in-the-know, when a different system would be just as easy and produce fairer results.</p>
<p>CF – There are three reasons it doesn’t work the way you suggest: 1. Most of the systems are intended to maximize the percentage of students who get their first choice, and your proposal would result (my guess) in that that percentage plummeting. 2. From the perspective of an individual school in high demand, you’d rather have a student population that strongly wanted your particular school, rather than a population where you’ve got a lot of students that ranked your school lower. (The schools that don’t fill/or are ranked poorly don’t particularly care either way.) and 3. From a district’s perspective, this reduces the apparent demand for highly popular schools, because families in-the-know learn that they can only put one highly popular school on their list. That’s the part that is particularly pernicious from my perspective.</p>
<p>The old system – where each school ran its own lottery, you produced a bunch of offers, and then the family chose the offer that seemed best was the one that maximized student choice opportunities, because if you liked the three most popular schools you could apply to all of them, and have an independent chance of getting an admission offer from each. Schools (other than the highly popular ones) and districts don’t like this model because it tends to take more iterations to get everyone settled, which makes scheduling a lot tougher. And, many times those opposed to school choice oppose school-run lotteries because they fear that they won’t be random.</p>
<p>I don’t know of any systems that handle it alphabetically – that would be grossly unfair, imo. And except for some test high schools and arts programs that require auditions, it is almost unheard of for a K-12 selection algorithm to consider student grades, test scores, gender, special ed, or ELL status. Some districts do include some surrogate for socioeconomic status, like free or reduced lunch, and a number use a “district” concept to prioritize kids geographically. The Office of Civil Rights gets pretty picky with districts that are involved in discriminatory selection systems, and there have been a number of consent decrees related to that. Even with kids on Special Ed plans, you most commonly see the child placed into the regular draw, and only after that child is matched to a school is there an assessment of whether or not that particular school is an appropriate placement. We tell schools never to ask if a child has Special Ed or ELL needs until after they’ve been offered enrollment – otherwise parents assume that if their child didn’t get in that it was because of discrimination. </p>
<p>And for districts (other than Zmom’s) that use sibling preferences, you’ve got all sorts of other factors, including the order in which you fill grade levels, which makes a huge difference in the outcome.</p>
<p>But students only get their “first” or “second” choice because students don’t put their real preferences on their list. That is, in-the-know students get their first or second choice, but only because their “first choice” might not really have been their first choice, and their “second choice” was really their fourth or fifth choice. The students are forced to guess and strategize under imperfect information, and if they guess wrong, they can be very disappointed.</p>
<p>My proposal will result in the student being accepted at his first choice of the schools still available to him or her. The current system doesn’t do that. For example, let’s say Britney’s true preferences were Stanford, Princeton, Williams, Michigan, Maryland-College Park, Penn State. </p>
<p>Under the current system, if she submitted that list, she might be lucky and get into Stanford. She would have no chance at all at Princeton or Williams, since those schools would be filled in the first round. She would also have no chance at Michigan or UMCP, since those would be filled in the second or third round. She’d probably end up at Penn State.</p>
<p>Suppose she was canny and in-the-know. She would pick one of Stanford, Princeton, and Williams for her first choice: perhaps, even though she really wanted Stanford, she’d be strategic and guess that Williams would give her a slightly better chance. Or maybe she’d put Stanford. Or maybe Princeton. For her second choice, she’d put Michigan. Or maybe she’d think that she’d have a better chance that Maryland was still open. Then she’d be put to the guess again for choice three-- how popular is Maryland? How popular is Penn State? Should she risk putting Maryland, knowing that Maryland might be full by the first round, and Penn State by the fourth round, and she’d get nothing? Or should she put Penn State, knowing that Maryland might have space in the third round, and she’d miss out? </p>
<p>So, she submits, let’s say,Stanford, Maryland, Penn State. Her name comes up in the first round: Stanford is full, but Williams had spaces. She wants to go there, but too bad for her, she guessed wrong. She’s back in the hopper. Her name comes up again in the second round. Now, Michigan is available, and Maryland not. Remember, she prefers Michigan to Maryland, but she guessed that Maryland would be less popular. She loses again. She ends up at Penn State, despite the fact that when her name came up, Williams still had spaces, and when her name came up again, Michigan had spaces, and she prefers both to Penn State.</p>
<p>The current system, then, requires students to do second-order strategizing. They have to figure out not only what they want, but what other students are going to want, and what other students think other students are going to want. It’s preposterous to make students play such a high-stakes game, and a lot of them end up losing for no reason.</p>
<p>Under my proposal, she puts down her actual list in her actual preference order. Then, when her name comes up, she gets to go to the first school on her list that still has openings. This has several advantages. First, not-in-the-know students have a chance to get in the schools which are popular but not the very most popular (like Michigan in my example). Second, students and their families don’t have to waste time strategizing on which list to submit.</p>
<p>“Good afternoon students, and welcome to the first day of school. As you are aware, you and your classmates were randomly selected to attend this school. I’d like to announce that in addition to your presence here being random, that grades, awards, and disciplinary actions will also be randomly assigned this school year.”</p>
<p>While it’s true that pupils, teachers, administrators, grades, awards, and yes even disciplinary actions are randomly assigned at some schools … my district comes to mind … no administrator or school board would ever suggest this could be true.</p>
<p>CF – believe me, I’m not defending the approach I described. I argued against it rather strongly. In particular, I think that it tends to adversely impact low-income students whose families are quite unlikely to have done the footwork to get familiar with these kinds of details. I’m not sure that a lot of district administrators really understand the ramifications either.</p>
<p>I see. They just want to claim that students get their “first” or “second” choice. They don’t understand what actually happens. How frustrating for you, and for the low-income students who are shut out of the popular schools.</p>
<p>“I see. They just want to claim that students get their “first” or “second” choice.”</p>
<p>A huge part of school administrator’s job is public relations. When an administrator is changed in our school district, poor public relations is ALWAYS the main reason. To a parent whose child has been inappropriately placed (in the parent’s mind) no administrator wants to tell the parent “It’s completely random assignment, and though I have the power to reassign the student, I’m not going to do that. Deal with it.” MUCH better to say “Ma’am, we assign students to the school that’s highest on their list, providing of course there’s a slot open there. Sometimes there isn’t. I’m sorry.”</p>
<p>Not everybody gets to be happy, but if they do it right, you couldn’t make everybody happier by e.g. exchanging any pair of students in different schools.</p>
<p>If the district is treating this as a combinatorial optimization problem, we can’t really talk about the probability of getting admitted into any given place. However, a game-theoretic approach could be fruitful…</p>
<p>^My impression is that it’s a game theory problem, but impossible to solve since they don’t tell you what the rules are. It appears to maximize getting people into one of their first five choices since that’s what they boast about, but it’s really anybody’s guess.</p>
<p>NYC uses the same sort of process as that used for medical residencies on match day. It DOES not hurt your chances to apply to your choices based on real preferences. It DOES hurt your chances if you don’t list enough choices. </p>
<p>It’s not totally random. Read the article above in the NY Times. Principals can, and do, take into account things like the number of times tardy or absent.</p>
<p>That would be true if they did it right. However, under the system arabrab describes, which she rightly condemns, there will be pairs who would prefer to exchange-- because savvy students don’t write down their actual preferences.</p>
Of course, the optimality of the solution to the stable marriage problem assumes that the people put down their actual preferences… I guess what I’m trying to say is that, without perfect information, the optimal strategy is probably to put down your actual preferences and hope for the best.</p>
<p>The system arabrab describes isn’t exactly the stable marriage problem (SM). In SM, both sides have an ordered preference list. In this case, only the students have a preference list; the schools merely have a set number of openings to be filled.</p>
<p>I say, in this situation zoosermom should find out the scuttlebutt about the optimal strategy. If the system is as arabrab describes, putting down one’s actual preference is fatal, whereas in a good system, putting down one’s actual preference is the best strategy.</p>