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updates for 03.06.2012

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Analyzing Released NYC Value-Added Data Part 3

The inaccuracy of the New York City teacher evaluation data is taking a beating in the media.  As I expected, this data would not stand up to the scrutiny of the public or even the media.  Value-Added is proving to be the Cathie Black of mathematical formulas. A teacher's Value-Added score is a number between about -1 and 1.  That score represents the amount of 'standard deviations' a teacher's class has improved from the previous year's state test to the current year's state test.  One standard deviation is around 20 percentile points.  After the teacher's score is calculated, the -1 to 1 is converted to a percentile rank between 0 and 100.  These are the scores you see in the papers where a teacher is shamed for getting a score in the single digits. Though I was opposed to the release of this data because of how poorly it measures teacher quality, I was hopeful that when I got my hands on all this data, I would find it useful.  Well, I got much more than I bargained for! In this post I will explain how I used the data contained in the reports to definitively prove:  1) That high-performing charter schools have 'better' incoming students than public schools, 2) That these same high-performing charter schools do not 'move' their students any better than their public counterparts, and 3) That all teachers add around the same amount of 'value,' but the small differences get inflated when converted to percentiles. In New York City, the value-added score is actually not based on comparing the scores of a group of students from one year to the next, but on comparing the 'predicted' scores of a group of students to what those students actually get.  The formula to generate this prediction is quite complicated, but the main piece of data it uses is the actual scores that the group of students got in the previous year.  This is called, in the data, the pretest. A week after the public school database was released, a similar database for charter schools was also released.  Looking over the data, I realized that I could use it to check to see if charter schools were lying when they said they took students who were way behind grade level and caught them up.  Take a network like KIPP.  In New York City there are four KIPP middle schools.  They have very good fifth grade results and their results get better as they go through the different grades.  Some of that improvement comes from attrition, though it is tough sometimes to prove this.  The statistic that I've been chasing ever since I started investigating these things is 'What were the 4th grade scores for the incoming KIPP 5th graders?'  I asked a lot of people, including some high ranking KIPP people, and nobody was willing to give me the answer.  Well, guess what?  The information is right there in the TDR database.  All I had to do was look at the 'pretest' score for all the fifth grade charter schools.  I then made a scatter plot for all fifth grade teachers in the city.  The horizontal axis is the score that group of students got at the end of 4th grade and the vertical axis is the score that group of students got at the end of 5th grade.  Public schools are blue, non-KIPP charters are red, and KIPP charters are yellow.  Notice how in the ELA graph, nearly all the charters are below the trend line, indicating, they are not adding as much 'value' as public schools with students with similar 4th grade scores. As anyone can see, the fact that all the red and yellow markers are clustered pretty close to the average mark (0 is the 50th percentile) means that charters do not serve the high needs low performing students that they claim to.  Also notice that since these red and yellow markers are not floating above the cluster of points but right in the middle of all the other points, this means that they do not 'move' their students any more than the public schools do.  And the public schools manage this without being able to boot kids into the charter schools. One other very significant thing I'd like to point out is that while I showed there was very little correlation between a teacher's value-added gains from one year to the next, the high correlation in this plot reveals that the primary factor in predicting the scores for a group of students in one year score is the scores of those same students in the previous year score.  If there was a wide variation between teachers' ability to 'add value' this plot would look much more random.  This graph proves that when it comes to adding 'value,' teachers are generally the same.  This does not mean that I think there are not great teachers and that there are not lousy teachers.  This just means that the value-added calculations are not able to discern the difference.  


Seeing the beauty in the hard times.

I went to yoga today for the first time since Ioana died. I knew something would make me cry in the middle of class before I went. Oh well. It's where I'm at. The moment I started crying in yoga was the mention of a "shoebox of photographs with sepia-toned loving" in this Jack Johnson song, Better Together. It reminded me so much of the people who spoke about how you made Andrew a better person and how he opened up your life. I hope that he'll grieve as hard for you as you would have for him and be left with some of the joy you gave him. The urge to run, to discover, to love, to learn. I don't think that your going will take away everything you gave him. I hope he'll find this eventually. The song spoke of love coming to someone in his dreams: I believe in memories They look so, so pretty when I sleep Hey now, and when I wake up, You look so pretty sleeping next to me But there is not enough time, And there is no, no song I could sing And there is no combination of words I could say But I will still tell you one thing We're better together. I hope Andrew finds you in his dreams and has strength to smile again. I don't know how that works-I've never lost a sibling spouse or parent. I don't think I'd have been able to leave my bed yet if it had been my brother. Ioana, I know that you left me with a very precious gift this week even as you took something very special from my life. My yoga teacher uses body poses to explain the contradictions of finding pain and joy in the same moment. As we hold a pose and our muscles burn and tire it is still possible to enjoy it and find peace and joy in the challenge. We are supposed to take the strength to find peace in yoga poses to our lives. I can imagine finding peace and joy as my body burns. I didn't know I'd be able to find any peace or love at the death of my friend. I wouldn't dare to describe my mood as happy as it wouldn't be true. And every time I accept that she is actually gone I feel empty and achy. When I see her mom's empty stare or I hold her crying sister, nothing in the world makes sense. But through all this pain there are still wonderful things. We seem to be at our best when life is a its worse. I've seen how much families can love each other. I've seen grown men hold hands and hug and cry and take care of each other. I've made new friends who are bright and kind and enthusiastic about life. I've seen people forget past conflicts and forgive each other. I've seen an entire room full of people talk of nothing but love and adventures and dreams and friendship and inspiration. I've seen another 250 people listen for three hours even though many of them were standing in spike heels because we ran out of pews. Everyone is patient, helpful, kind. Everyone is dreaming about what they can accomplish. People are hiking, painting, writing, loving, cooking, eating and jumping into freezing pools with their closest friends in March at a celebration of your life after we buried you. Ioana gave us so much when she was alive. She convinced many to run. To hike to the bottom of the grand canyon. To study. To play in cold water. To express love openly. To keep memories alive in photographs. To wake up early and see the sunrise on the walls of the canyon. She even convinced my shy boyfriend to dance at her wedding! Who could refuse such a bride? With her death she gave me more than I could possibly imagine. I never would wish anyone's passing so that we might appreciate our loved ones more, but since I have no control over her death I can only try to thank her for how it influenced me. Thank you Ioana, for how much I love my Andy, my friends and my family. For appreciating the feel of my body as I ride my bike in the sun. For realizing that most of everything that I'm ever annoyed about doesn't really matter. For inspiring me to leave the computer and sit and talk to my loved ones. Thank you Ioana for gathering all of your loved ones together so I might get to know all of the wonderful people who came to celebrate your life. I wish I'd met them in a happier time. Thank you for inspiring me to be less preoccupied with things I can't control, less worried about my future and more willing to seek friendship and joy without shyness. I can't accept that your life was meant to be short, vivid and wonderful because of the pain I've witnessed this week. Parents should never bury their children. I have to accept that we are meant to learn something from this tragic accident. Since you left me only with memories of your vivacious life, I suppose the best I can do is learn how to love harder and live more for you. Thank you Ioana for all of the love you inspired this week-I don't know how we'd get through all of this pain without it. Love is the answer, At least for most of the questions in my heart Like why are we here? And where do we go? And how come it's so hard?


So level-headed.

I am notoriously unfeeling. Alexis says, "But that's just Caroline," whenever someone complains about me seeming callous. I can be pretty excellent at eliminating emotion and getting down to it, tearing through problems and blatantly telling people they're wrong. But every once in a while something will sneak up, and it's like having  thumbs gripping your shoulder-blades and fingers stretched from behind, across collar bones, then slamming you down into the earth. You're wrong. I can't imagine the high school teachers, when grades and graduation become so intense, and parents spit fire about homework. This is a new feeling, to give a student a zero because no name was placed on it and have a very rational parent who I have had a great relationship call today to first tell me she would directly refuse to schedule a meeting to discuss it ("I'm coming now"), second hang up on me mid-sentence, and third say about my policies, "But doesn't that sound insane?" Well, no. Not if your child wants to succeed in college, or life, or get any credit for a scholarship application or anything else important. If she doesn't learn to put her name on her paper now, even if it's the first and only time she forgot, when will she? Granted, I'm stubborn. Stubborn because I'm obsessed with rules, because I like having reasons for things, I like black and white. All other students that didn't put names on got zeros because I threw their paper out. This girl's I happened to give back because I recognized her handwriting. Mistake. But I completely appreciate and admire the determined parent. I would much, much rather have this than the parent I've literally been calling twice a week for the past five weeks all to no answer. Last, if you're wondering how Brax is doing...


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