中國的教育更像一棵畸形的盆景

中國的教育更像一棵畸形的盆景 　　
多年來，在國內的教育中，存在著各種怪象：
上條件好的幼兒園要交數額不菲的贊助費；老師平時對孩子的態度取決於家長的背景；中高考需托關系、交擇校費進名校；老師對日常教學得過且過，把大量時間和精力放在從課外補習班上多掙灰色收入……

Struggling pupils 等待台灣教育失效的分析

我沒見過類似的台灣教育失效的分析

Struggling pupils don't catch up, data shows

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By Hannah Richardson and Katherine Sellgren BBC News

This year's tables feature far more data than in previous years

Continue reading the main story

School league tables

• Two grammars top league tables
• Best GCSE results
• Lowest GCSE results
• Regional picture: GCSE results

Just one in 15 (6.5%) pupils starting secondary school in England "behind" for their age goes on to get five good GCSEs including English and maths, official data shows.

The government data published as part of secondary school league tables suggests the majority of schools are failing struggling pupils.

Nationally 58.2% of pupils reach the five good GCSEs benchmark.

Minister Nick Gibb said schools which let pupils down would be tackled.

The Department for Education data covers England's more than 5,000 secondary schools with more than 200 pieces of information being published for each one - almost four times as much as last year.

Much of the information is broken down by pupil type, with scores offered for low, medium and high-attaining pupils, and those from disadvantaged backgrounds as well as non-disadvantaged.

As expected, those from disadvantaged backgrounds (classed as those on free school meals or in local authority care) do less well.

Continue reading the main story

England league tables

Secondary schoolsPrimary schools

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Only a third (34%) of these children achieve the government's benchmark of five GCSEs - or equivalent qualifications - graded A* to C, including English and maths.

In 909 schools, not one low-attaining pupil (those who did not reach Level 4 at the end of primary school) reached this threshold.

At the other end of the spectrum, 95% of pupils who started school "ahead" for their age (achieving Level 5 at the end of primary school) got five good GCSEs, including English and maths.

And of those who started school at the expected level for their age, (Level 4 at the end of primary school) some 45.6% failed to progress to five good GCSEs.

Overall, 58.2% of pupils in England's state schools got five good GCSEs including English and maths (including equivalent qualifications).

'One chance'

When these qualifications, such as BTecs and NVQs, are excluded, 52.4% of pupils gained five good GCSEs.

The performance data also shows what proportion of pupils get the English Baccalaureate.

This new measure, introduced in 2010, is the proportion of pupils achieving A*-C passes in English, maths, two science subjects, a modern or ancient language, and either history or geography.

Nationally across all pupils, just 15.4% got the wrap-around qualification, but most pupils would have made their GCSE choices before Education Secretary Michael Gove announced he was introducing this certificate of achievement.

Pupils with low prior attainment also performed poorly in the English Bacc, with just 0.3% gaining the wrap-around qualification.

Sevenoaks School, a private school in Kent, tops the English Bacc tables, with 99% of pupils meeting this benchmark.

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Brian Lightman: "Government needs to spend less time blaming schools"

Schools Minister Nick Gibb said: "Today's figures reveal a shocking waste of talent in many schools across the country. All too often, pupils from disadvantaged backgrounds aren't given the same opportunities as their peers.

"But there are great examples of schools achieving the best for their disadvantaged pupils. If they can get it right, then so can all schools."

The government says its data shows there are 107 secondary schools below the floor standard of 35% of pupils getting five good GCSEs, including English and maths.

Top performers

Mr Gibb added: "Children only have one chance at education. These tables show which schools are letting children down. We will not hesitate to tackle underperformance in any school, including academies.

"Heads should be striving to make improvements year on year, and we will not let schools coast with mediocre performance."

Shadow education secretary Stephen Twigg said that while many pupils, especially those from disadvantaged backgrounds are not achieving their potential, the government is promoting pet projects over real need.

"The government needs to focus on the 3Rs as well," he added.

Continue reading the main story

HEADLINE SCORES

• National average for five good GCSEs: 58.2% of pupils
• National average for English Baccalaureate: 15.4%
• Best GCSE performance: Lawrence Sheriff Grammar School, Rugby
• Worst GCSE performance: St Aldhelm's Academy, Poole
• Best A-level performance: Colchester Royal Grammar School, Essex
• Best performing local authority: Sutton, London
• Worst performing local authority: Knowsley, Merseyside

NUT general secretary Christine Blower said the social inequalities with which children start school, widen as they progress through their education.

"Instead of focusing on changing school structures and on the pointless naming and shaming of schools, the Government should be ensuring that all schools have the resources and support they need for all pupils to reach their full potential."

In total, 158 schools see 100% of pupils getting five GCSEs A*-C or equivalent, including maths and English.

When the average point score per pupil is used to rank these top performers schools, Lawrence Sheriff Grammar School in Rugby comes top.

Head teacher Dr Peter Kent said much of the school's success was down to Key Stage 4 being spread over three years rather than the traditional two.

"This gives departments a chance to deliver a very personalised curriculum and we all respond well to something that's been tailored to our individual needs," he said.

The poorest performing school was St Aldhelm's Academy in Poole, Dorset, where just 3% of pupils got five GCSEs A*-C or equivalent, including maths and English.

Principal Cheryl Heron, who took over in September 2010, said the results were "disappointing but not unexpected". It would take time to change and transform pupils' learning experiences, she added.

'Focus'

At sixth form level, the Colchester Royal Grammar School in Essex comes out as the best performer, with an average point score per pupil of over 1,477 - this is the equivalent of over four A*s and one A grade at A-level.

The best performing county was Sutton in London, where 74.7% of pupils got the government benchmark of five GCSEs, including maths and English. The worst was Knowsley, Merseyside, where 40.8% of pupils reached this level. A Knowsley spokesman said its schools were improving year after year.

Your comments (778)

how much the quality of individual teachers matters over the long term.

BIG STUDY LINKS TEACHERS TO LASTING GAIN
WASHINGTON — Elementary- and middle-school teachers who help raise their students’ standardized-test scores seem to have a wide-ranging, lasting positive effect on those students’ lives beyond academics, including lower teenage-pregnancy rates and greater college matriculation and adult earnings ,according to a new study that tracked 2.5 million students over 20 years. The paper, by Raj Chetty andJohn N. Friedman of Harvard and Jonah E. Rockoff of Columbia, all economists, examines a larger number of students over a longer period of time with more in-depth data than many earlier studies, allowing for a deeper look at how much the quality of individual teachers matters over the long term. The article is in The New York Times.

Japanese strategy for improving teachers is catching on in Chicago

By Linda Lutton

Math teacher Michael Hock during a class he taught for a lesson study session. Other teachers gauge his success. (Photo by Linda Lutton/WBEZ)

In the sunlit library at Jorge Prieto Elementary on Chicago’s’ northwest side, an experiment is under way.

A provisional classroom has been set up. A white board sits at the front of the room, and 20 eighth-graders are seated at library tables. Math teacher Michael Hock is giving a lesson about the distributive property.

Scattered throughout the room are some 30 other teachers. They aren’t wearing lab coats—but they might as well be. They clutch clipboards and carefully monitor kids’ reactions to the teacher’s explanations, peering over students’ shoulders as they write answers.

“What is the area of the garden?” Hock asks students as he points to an illustration on the white board. “Nestor, I haven’t heard from you today.”

Listen to the audio story

Nestor answers the question, and the 30 adults, including visiting teachers from Japan, scribble notes.

The exercise is called “lesson study.” It’s a professional development strategy used extensively in Japan that essentially dissects a teacher’s lesson and the way it’s delivered.

Here’s how it works: teachers come up with a detailed lesson plan and explain ahead of time to colleagues the goals of the lesson. Then, one teacher tries the lesson out on a group of students, while dozens of other teachers watch what happens.

Teachers observe students during a lesson study session at Jorge Prieto Elementary last summer. (Photo by Linda Lutton/WBEZ)

Finally, the observers offer feedback and ideas for improvement.“[We’ve been] doing lesson study more than 100 years in Japan,” says Toshiakira Fujii, a premier professor of math education in Japan who was among those teachers observing at Prieto. “But lesson study in the United States is quite new.”

Fujii says Japanese teachers see lesson study as a proving ground, a way to shine in front of their colleagues.

“You can see [it] everywhere in Japan,” says Fujii. “In Tokyo in the case it’s Wednesday. Wednesday [we] usually finish at lunch time. Then one class stays, and the other classes dismiss. And then every teacher comes to that one class and observes. Even the school nurse and school counselor also join to watch the lesson—that’s our traditional way.”

There’s been lots of talk about how Chicago should evaluate teachers. Lesson study is being billed as a way to help teachers improve.

The strategy is one both teachers unions and school districts say they like. The head of instruction in Chicago Public Schools says she’s a fan of lesson study. The Chicago Teachers Union helped organize the lesson study at Prieto—and convenes other sessions on holidays like Pulaski Day, when students and teachers volunteer to participate.

Florida included lesson study in its winning Race to the Top proposal.

After a lesson is taught and students dismissed, teachers analyze what happened. They’re like scientists looking back at their experiment, figuring out what went right, what went wrong.

Teacher Michael Hock (right) hears feedback from teachers on the lesson he taught. That can take "thick skin," he says. (Photo by Linda Lutton/WBEZ)

“Possibly you forgot—or you chose not to—ask the students to draw a model of the equation,” one teacher tells Hock after students at Prieto have left the library.

“I didn’t see much evidence that they felt challenged,” adds another, citing his extensive notes. “I know there was some discussion at two of the tables, but there didn’t seem to be very much discussion at three of them.”

The teachers discuss whether it was more successful to use concrete examples or abstract ones and whether the illustration Hock used helped students understand the concept being taught.

“I really love it because it’s all about constructive feedback,” says Hock. But he admits it can require some thick skin at times. “Because you’re going to hear some things. I mean, some people like that constructive feedback and some people are like, ‘Whoa, I hate that. It kind of points out all the things we did wrong.’ I don’t look at it that way.”

Hock was criticized the day prior for talking too much while teaching.

“But today when you were walking around between desks—you stopped talking,” Fujii told him during the feedback session. “You can change your behavior by one day. That’s amazing.”

Margaret O’Sullivan, who teaches sixth-grade science at Armstrong Elementary in Rogers Park, says participating in lesson study has changed her whole thought process as a teacher.

“Now I’m thinking before I start the lesson, ‘OK, these are the questions I’m going to ask.’ And not just questions where they give you back facts. But questions that are going to lead them to more deeper thinking.”

O’Sullivan says it’s difficult for teachers to get thoughtful feedback on their day-to-day work. Many principals observe teachers just once a year.

“When you’re in the classroom, you’re only limited to what you see, so you may miss out on a lot of what’s going on,” says O’Sullivan. “So after doing a lesson to step back and have people point out things that you may not have noticed is incredible feedback that you just don’t get.”

Lesson study advocates in Chicago hope to spread the practice further. As Chicago shifts to new “common core” learning standards, advocates hope lesson study might play a role in helping teachers teach to the more rigorous standards.

Chicago has its own lesson study guru. DePaul University education professor Akihiko Takahashi is known internationally for promoting lesson study. Here, he’s co-founded the Chicago-based Lesson Study Alliance, and he’s on a mission:

“Traditional American professional development is somebody outside comes and then does for teachers,” says Takahashi. But he argues there is a lot that teachers can do on their own. “My goal is in every school teachers gather and then find a new way to improve lessons by themselves.”

And what do students think of lesson study?

It feels “weird” having all those adults milling about, peering over students’ shoulders, says Prieto eighth-grader Hector Figueroa. But, he adds, “you get used to it.”

Hector’s teacher told kids they should just think of the adults as “flies on the wall.”

“But that would be even freakier,” Hector says. Still, he gets the point: “I think they’re just trying to make our teachers better.”

This story aired on WBEZ on January 9, 2012. It was produced with support from The Hechinger Report.

平板電腦的內文

新竹市園區學校每位學生獲贈的平板電腦是那一品牌?

Apple Makes Push Into iPad Textbooks

Apple introduced tools designed to spur the development of textbooks and other classroom materials for the iPad, a push to drive demand for its tablet and change the education market.

倪明選談"學術界經驗"

nascence,research,re-

港科大教授倪明選談"學術界生存經驗"
2006年11月06日 07:21:48 　來源：中國青年報
【字號 大 中 小】　【我要打印】　【我要糾錯】	【Email推薦： 】

論文讀得太多，會被洗腦，優秀的學生變成平庸之輩。11月3日，在華中科大舉行的2006光電子信息與技術全國博士生學術論壇上，國際知名計算機專家、香港科技大學倪明選教授，結合自己的經歷，與博士生暢談“學術界生存經驗”。

倪明選指出，很多年輕的學者都會認為，選課題前別人的論文讀得越多越好，實際上這 是一個很大的誤區，只會給自己“洗腦”，喪失自己的想法。“最恰當的研究方法應該是精選一定量的好論文，邊閱讀邊思考，這會給自己很多啟發。”他告訴在場 的博士生，自己曾經有不少特別優秀的學生，就因為過度閱讀他人的論文而變得平庸。

怎樣做好研究？怎樣選出好的研究課題寫出好的論文？倪明選認為，首先要確信自己已經為開展科學研究做好了充分的準備，即已經精通基本技巧、具備進一步學習的能力；其次則要有開放的思維，這樣才能有新奇的想法；再次，要有批判的思想，這樣才能對事物有更深刻認識。

倪明選告訴廣大博士生，“選課題是研究的開始，是做好研究很重要的一個部分”。根據自己的經驗，他指出，“興趣是動力的源泉，找課題一定要根據自己個人的興趣來；同時還要兼顧所選課題是不是符合自己的水平，這樣才有利于自己的研究。”

課題選好了，那麼在課題研究中好的想法從何而來？倪明選提出了4個觀點：喝喝啤 酒，放松一下，在放松中更容易找到靈感；靈感從天而降，就像牛頓發現萬有引力定律一樣，知識越多，我們就越善于獲得從天而降的靈感；懂得目前的工作情況， 在工作中慢慢積累；對自己的研究課題一定要有深層次的認識，同時擁有廣博的知識面。

“要有好的想法並不難。”倪教授這樣告訴在場博士生，“只要注意到上面幾點，同時注意一下研究的方法，就很容易想到好的主意了。”

倪明選還通過對英文“研究”的巧妙解構，詮釋了他眼中的研究。

“研究的英文拼寫research＝re＋search。”創新、創造、合作，加上反復地探索，這就是研究的態度，“如果能夠做到這一點，我們都能做出成果。”

針對目前在部分研究生與導師之間存在的“代際關係緊張”問題，倪明選認為，這樣很不利于自己的研究。因為在學習階段，很多東西還是需要導師輔導的。要處理好與導師的關係，也不是唯導師之命是從，有自己的觀點一定要敢于提出。

對此，他講到自己經歷的一件事情：有一個學生曾經向自己提出過一個很新的觀點，當時自己也沒有很在意，認為沒有什麼研究價值，但是這個學生沒有放棄，最終他在這個方面做出了很重要的研究成果。（通訊員 朱俊剛 陳婧婧 記者 甘麗華）

"工程經濟學""系統學/分析"

陳寬仁教授給我 "給力春聯" 他還做些補充 我也順便再多談點
關於MTM的領域 我跟林公說美國這些科學 最重要的其實是方法學 而非那些東西本身 而日本人/工程師 將類似的想法應用在"容易裝配能力" 等方面.....

我還跟陳老師談他最擅長的"工程經濟學" 我說它沒整合進 "系統學/分析"等是很遺憾的課程設計之失"

(另一方面 小燕等東海建築系的畢業生 出外做是經常碰到工程經濟的問題 可是她們根本沒學過 其實只要幾小時的課程 就很有注意了)

我還跟陳老師談中鋼公司的兩位董事 一個是現在90幾歲的雷穎將軍 它的回憶錄有趙耀東先生1973年到東海的感人演講 (他改變了我 詳2008年的抒) 以及我與盧淵源教授的一席話 它如何在中華汽車受林信義之重視 得以代表經濟部.....

MTM 記得似乎是 Method-Time Measurement

簡立當年為遷院， 原來想要100甲。 後來圈得員樹林的相思林及一小部分茶園圃，一共是67甲。他邀請林務局專家來指導種樹。樹種繁多。經過數十年，現在校園植被非常茂盛美麗。圖書館旁邊是片比足球場還大的青草坪，大禮堂前有珍貴到以寸計價的南洋杉，林務局選作試驗對象的台灣黑松林，航空安全教學大樓前面是一片橄欖樹，‧‧‧　‧‧‧　。每年春天杜鵑花盛開時，校園開放參觀。

簡立對學術界二大貢獻： 一、是將隸屬於陸軍的「陸軍理工學院」晉名為 「中正理工學院」直屬國防部，把陸海空的理工教育溶合， 為中山科學院供應人力。 二、是把淡江文理學院昇格為淡江大學。　另有二件創舉：一、中正理工學院向日本日立公司購買電子顯微鏡，

是台灣第一台。　二、淡江大學管理科學研究所與國防部簽約合作十年(民國60-70年)

Phi Delta Kappa /Phi , Tau , Phi /Sigma Xi/Phi Beta Kappa

Phi Beta Kappa

(fī)
n.

1. An honorary society, founded in 1776, of college students and graduates whose members are chosen on the basis of high academic standing.
2. A member of this society.

[From the initials of the society's motto in Greek philosophiā biou kubernētēs, philosophy the guide of life : philosophiā, philosophy + biou, genitive of bios, life + kubernētēs, guide.]

Sigma Xi: The Scientific Research Society is a non-profit honor society which was founded in 1886 at Cornell University by a junior faculty member and a handful of graduate students.^[2] Members elect others on the basis of their research achievements or potential. Despite the name, Sigma Xi is neither a fraternity nor a sorority, and today is open to all qualified individuals who are interested in science and engineering.

民國十年五月二十五日，我國天津北洋大學美籍教授愛樂斯 ( J . H . Ehlers )致函國內各大學發起全國勵學會之組織，曾名定為斐陶斐，即希臘艾字母 Phi , Tau , Phi 之譯音，用以代表哲學、工學、理學( Philosophia , Technologia , Physiologia ) 三種學術 。

哲學為科學之母 ; 工學即工藝之學，為應用科學 ; 理學即生理學，為純理論科學。本會籌備期間，由愛樂斯氏親任總幹事之職，教育總長范德源、南京高等師範學校校長郭秉文、國立北京大學教授胡適、南開大學校長張伯苓、燕京大學校長司徒雷登、聖約翰大學校長卜舫濟、金陵大學校長包文為第一屆董事會籌備會員。

Phi Delta Kappa (also known as "PDK" or "PDK International") is an US professional organization for educators. Its headquarters are located in Bloomington, Indiana. It was founded on 24 January 1906. Phi Delta Kappa also had a youth organization, called Xinos, girls, and Kudos, guys.^[1]

Phi Delta Kappan

www.kappanmagazine.org/ - Cached

Not a PDK member? Join now to receive Kappan magazine and other great member benefits. Phi Delta Kappa International. CONNECT WITH US; PDK Blogs ...

Harvard Educational Review (1930-)《北京大学教育评论》（季刊2003-）

Harvard Educational Review - Harvard Education Publishing Group

www.hepg.org/her - 頁庫存檔 - 翻譯這個網頁

A scholarly journal on education; provides an interdisciplinary forum for discussion and debate about education's most vital issues. Founded in 1930, the Review ...



2003 年 7 月，国家新闻出版总署致函教育部，批准创办《北京大学教育评论》（季刊）。由汪永铨教授任主编，喻岳青教授任常务副主编。

发 刊 词

　　百年大计，教育为本。江泽民同志指出，要发展我国的教育事业，就“必须不断推进教育创新”，而教育的创新须臾离不开教育科学研究。对此，北京大学责无旁贷。一份《北京大学教育评论》，正是对繁荣中国教育研究，推进中国教育创新这一使命的一份承诺。
　　教育学科在北京大学源远流长。早在京师大学堂时期便设有师范馆，1924年正式设立教育学系。在20世纪上半叶，无论在教育理论研究，还是在教育实 践，或是在教育国际交流方面，北京大学都有令人瞩目的贡献。1949年，根据政府的统一规划，北京大学取消了教育系科。三十余年之后，根据教育事业发展的 需要，教育学科在北京大学又逐步得到重建：1973年建立电教组（后改为电化教育中心），1980年建立高等教育研究室，1984年建立高等教育科学研究 所，1999年建立教育经济研究所，2000年建立教育学院。至此，教育学科已跻身于北京大学当前基本学科之列。本刊的创办，正是教育学科在北京大学成长 壮大的一个标志。
　　本刊旨在促进教育领域的科学研究与交流，特别注重教育研究的创新性、学术性、实践性和跨学科性。
　　创新是科学研究的生命所在，是独立思考和深入探索的结果，也是学术讨论与交锋的结果。而这些都离不开百家争鸣的学术氛围。本刊有志于为教育界同人创造一个宽松活跃的学术空间，为推动我国教育理论与实践的创新而努力。
　　学术性是对学术研究的基本要求，一切论点和结论都应当建立在专门而深入的研究之上，实事求是，言之有据，符合学术研究的方法与规范。本刊愿与诸位作者一起，致力于提高我国教育研究的学术水准。
　　实践性是教育研究的根本归宿。学术研究不意味着远离实际，钻进与世隔绝的象牙之塔。恰恰相反，它应当根置于现实的土壤，汲取生活的养分，并最终以解决实践中的问题为依归。学术性与实践性的统一是我们的追求。
　　跨学科性针对的是画地为牢式的研究。教育研究应当超越人为的学科藩篱，倾听不同学科的声音，与其联手合作。同时，教育研究从来都不是教育研究者独有的 领地，不少相关的学科均为教育研究做出过重要贡献。我们相信，跨学科的视野和方法将会使教育研究更趋深入、广阔，更富活力。
　　本刊刊名题字由蔡元培先生遗墨集字而成，意在承续先生所奠定的民主开放的学术传统。我们创办这份刊物，决不是要营造一处私家的花园，而是要为教育界乃 至关心教育的各界同人创造一片公共的园地。希望专家学者和各界人士踊跃来此播种、耕耘和收获，与我们一起打造一份高质量的《北京大学教育评论》。

良師價無窮Big Study Links Good Teachers to Lasting Gain

Big Study Links Good Teachers to Lasting Gain

By ANNIE LOWREY

Published: January 6, 2012

WASHINGTON — Elementary- and middle-school teachers who help raise their students’ standardized-test scores seem to have a wide-ranging, lasting positive effect on those students’ lives beyond academics, including lower teenage-pregnancy rates and greater college matriculation and adult earnings, according to a new study that tracked 2.5 million students over 20 years.

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Steve Hebert for The New York Times

A study found profound effects on students whose teachers helped them raise their test scores.

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Benefits of Good Teachers

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The paper, by Raj Chetty and John N. Friedman of Harvard and Jonah E. Rockoff of Columbia, all economists, examines a larger number of students over a longer period of time with more in-depth data than many earlier studies, allowing for a deeper look at how much the quality of individual teachers matters over the long term.

“That test scores help you get more education, and that more education has an earnings effect — that makes sense to a lot of people,” said Robert H. Meyer, director of the Value-Added Research Center at the University of Wisconsin-Madison, which studies teacher measurement but was not involved in this study. “This study skips the stages, and shows differences in teachers mean differences in earnings.”

The study, which the economics professors have presented to colleagues in more than a dozen seminars over the past year and plan to submit to a journal, is the largest look yet at the controversial “value-added ratings,” which measure the impact individual teachers have on student test scores. It is likely to influence the roiling national debates about the importance of quality teachers and how best to measure that quality.

Many school districts, including those in Washington and Houston, have begun to use value-added metrics to influence decisions on hiring, pay and even firing.

Supporters argue that such metrics hold teachers accountable and can help improve the educational outcomes of millions of children. Detractors, most notably a number of teachers unions, say that isolating the effect of a given teacher is harder than it seems, and might unfairly penalize some instructors.

Critics particularly point to the high margin of error with many value-added ratings, noting that they tend to bounce around for a given teacher from year to year and class to class. But looking at an individual’s value-added score for three or four classes, the researchers found that some consistently outperformed their peers.

“Everybody believes that teacher quality is very, very important,” says Eric A. Hanushek, a senior fellow at the Hoover Institution at Stanford and longtime researcher of education policy. “What this paper and other work has shown is that it’s probably more important than people think. That the variations or differences between really good and really bad teachers have lifelong impacts on children.”

The average effect of one teacher on a single student is modest. All else equal, a student with one excellent teacher for one year between fourth and eighth grade would gain $4,600 in lifetime income, compared to a student of similar demographics who has an average teacher. The student with the excellent teacher would also be 0.5 percent more likely to attend college.

Perhaps just as important, given the difficulty of finding, training and retaining outstanding teachers, is that the difference in long-term outcome between students who have average teachers and those with poor-performing ones is as significant as the difference between those who have excellent teachers and those with average ones, the study found.

In the aggregate, these differences are potentially enormous.

Replacing a poor teacher with an average one would raise a single classroom’s lifetime earnings by about $266,000, the economists estimate. Multiply that by a career’s worth of classrooms.

“If you leave a low value-added teacher in your school for 10 years, rather than replacing him with an average teacher, you are hypothetically talking about $2.5 million in lost income,” said Professor Friedman, one of the coauthors.

To do the study, the researchers first tackled the question that has swirled controversy in so many school districts, including New York City’s: whether value-added scores are in fact a good measure of teacher quality. Mr. Jones might regularly help raise test scores more than Ms. Smith, but maybe that is because his students are from wealthier families, or because he has a harder-working class — factors that can be difficult for researchers to discern.

While Professor Rockoff, at Columbia, has previously written favorably about value-added ratings, the Harvard pair were skeptics of the metrics. “We said, ‘We’re going to show that these measures don’t work, that this has to do with student motivation or principal selection or something else,’ ” Professor Chetty recalled.

But controlling for numerous factors, including students’ backgrounds, the researchers found that the value-added scores consistently identified some teachers as better than others, even if individual teachers’ value-added scores varied from year to year.

After identifying excellent, average and poor teachers, the economists then set out to look at their students over the long term, analyzing information on earnings, college matriculation rates, the age they had children, and where they ended up living.

The results were striking. Looking only at test scores, previous studies had shown, the effect of a good teacher mostly fades after three or four years. But the broader view showed that the students still benefit for years to come.

Students with top teachers are less likely to become pregnant as teenagers, more likely to enroll in college, and more likely to earn more money as adults, the study found.

The authors argue that school districts should use value-added measures in evaluations, and to remove the lowest performers, despite the disruption and uncertainty involved.

“The message is to fire people sooner rather than later,” Professor Friedman said.

Professor Chetty acknowledged, “Of course there are going to be mistakes — teachers who get fired who do not deserve to get fired.” But he said that using value-added scores would lead to fewer mistakes, not more.

Still, translating value-added scores into policy is fraught with problems. Judging teachers by their students’ test scores might encourage cheating, teaching to the test or lobbying to have certain students in class, for instance.

“We are performing these studies in settings where nobody cares about their ranking — it does not change their pay or job security,” said Jesse Rothstein, an economist at the University of California, Berkeley, whose work criticizing other value-added assessments unions frequently cite. “But if you start to change that, there is going to be a range of responses.”

Many other researchers and school administrators say that even if imperfect, well-calculated value-added scores are an important part of evaluating teachers.

“Very few people suggest that you should use value-added scores alone to make personnel decisions,” Dr. Hanushek, of Stanford, said. “What the whole value-added debate has done is push forward the issue of how to evaluate teachers, and how to use that information.”

The new study found no evidence for one piece of conventional wisdom: that having a good teacher in an early grade has a bigger effect than having a good teacher in later grades.