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Can a good teacher change a student for life?

A new study links teacher impact not just to students' academic performance but to other, life-long benefits.
REUTERS/Swoan Parker
A new study links teacher impact not just to students' academic performance but to other, life-long benefits.

Today's New York Times carries a story about an important study that links teacher impact not just to students' academic performance but to life-long benefits including higher earnings, lower teen pregnancy rates and college enrollment.

A key finding, as reported by the paper: Replacing a poor teacher with an average one would raise a single classroom's lifetime earnings by about $266,000.

Other researchers have made the same controversial link in the past, but by tracking 2.5 million students over 20 years the new study is the weightiest yet.

And it has immediate ramifications for Minnesota policymakers and educators, who are in the final month of grappling with the thorny issue of how to use the same type of "value-added" data to evaluate the state's teacher and principal corps.

A state task force is currently working to devise an evaluation model to provide school districts that do not have their own systems for measuring teachers' impact on individual student achievement. The group is supposed to present its recommendations during the next legislative session, which begins at the end of the month.

The upshot, according to several Twin Cities educators familiar with the research: Proceed, but carefully.

Because they measure individual students' learning over the course of an academic year, not grade-level proficiency, so-called growth model or value-added tests are a fairer way to assess teachers' impact, they said.

But they are still imperfect, and using them to make high-stakes decisions about hiring and firing is fraught.

Minnesota needs to look carefully at the data-scrubbing and other methodologies employed by the study's authors, economists Raj Chetty and John Friedman of Harvard and Jonah Rockoff of Columbia, local educators said.

All kinds of variables
The economists controlled for all kinds of variables, including poverty, and used outcomes from multiple classes taught by each teacher to compensate for the inability to randomly assign students, some of whom are much harder to teach than others, to classrooms.

"I think it's yet another example of very careful work that shows that, at least in reading and math, and at least in grades 3-8, this can be done in a way that controls for biasing characteristics that students bring into the classroom," said Kent Pekel, executive director of the College Readiness Consortium at the University of Minnesota.

"It's a kind of numeric validation that the Jaime Escalantes of the world do exist and that they matter," he said, referring to the heroic teacher portrayed in the movie "Stand and Deliver."

Test data should be only a portion of any teacher's evaluation, he and other local education policymakers agreed. Observation by principals and peers and other measures are crucial both to ensuring decisions about hiring, firing and compensation are fair and to gleaning insight into great teachers' practices.

Right now, even the best value-added tests have too much margin for error, said Jim Angermeyer, director of Research and Evaluation for Bloomington Public Schools and a designer of one of the earliest and most reliable growth-model tests.

"It's not the sort of thing I would base personnel decisions on," he said. "The variability is just huge."

Economists love the kind of research featured in the Times today because it typically provides great insights. But breaking down statistics on, say, crime or recidivism rates and then probing for causes and correlations is more easily done objectively than in education.

Kids will not perform the same way on the same test from one day to another and a classroom contains few enough students that a poor performance by just a couple can have an outsize impact on an individual teacher's performance profile, he said. 

Plus, you have no guarantee the classroom teacher was the only, or most impactful, instructor. "If you have a classroom full of kids with serious problems, they may be receiving multiple levels of service from a variety of providers," he said. 

"You can be a great teacher one year and underperform in another," he said.

Ahead of the curve
Even with all of these caveats, Minnesota is ahead of the curve, Angermeyer and Pekel agreed.

As a part of the Bush Foundation's ongoing effort to increase the quality of teacher-preparation programs in the Upper Midwest, the nation's foremost value-added data experts are working with a number of districts throughout the state to tie student performance to teachers and to the institutions of higher education where the teachers received their training.

The foundation has contracted with the Value-Added Research Center (VARC), located at the University of Wisconsin-Madison. Center Director Robert Meyer was quoted approvingly in today's Times story.

Locally, VARC is working with Dave Heistad, Minneapolis Public Schools' director of Research and Evaluation, who is widely acknowledged to be the Minnesotan with the most experience parsing growth-model data.

Last year, he and Meyer provided some two dozen Minnesota districts with data showing the effectiveness of different grade-level teaching teams, Heistad said. Minneapolis is currently working on tying data to individual teachers.

Eventually, VARC's Minnesota research is expected to identify great teachers, any unique or effective preparation that went into making them great and whether the highest performers stay in the profession, Heistad said.

The model has tremendous potential, all three agreed, but the state task force at work right now needs to understand that the new study, and for that matter VARC's work, is very tricky stuff.

For instance, the study was the product of three highly skeptical world-class experts who imagined they would end up debunking earlier efforts, Pekel noted. They used retroactive data and controlled for myriad variables — which has important differences from using the data on the fly to evaluate teachers.

"What we should do is use this data as soon as possible to identify the most effective teachers and learn from them," said Pekel.

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Comments (8)

And BAD teachers can make a lifelong impact too. After having attended too many MPLS public schools, I can attest to this - - I was an "A" math student and one of the few girls recommended for Algebra in a North Mpls Jr high. I was struggling when my algebra teacher was in a bad car accident and was out for six weeks. The sub covering for her explained to me that I was just having difficulty with the formulas and gave me a new way to work things out using new formulas. I began getting all my answers right and grasping Algebra.
Well, then my old Algebra teacher returned and told me in no uncertain terms that she "didn't care" if I got the answers right. If I "couldn't do it using (her) formulas, she'd fail me" and that she did. In six months I went from being an "A" math student to an "F." I never ever took another math class and spent the rest of my life avoiding Math situations, and this leaked into my parenting when my children needed Math help. To this day I am not Math Anxiety, I am Math Anguish. Thank you Ms. H--Man! And thank you, Mpls Public Schools - -I made DAMN sure my kids NEVER went to these schools. And, thank God for that! My son, who grew up amidst the anguish this caused me, managed to supersede that damage and is now a highly regarded Finance Prof at an Illinois college. And, despite being a published writer and successful artist, I still suffer that feeling of educationally cultivated shabbiness, dislocation, and ashamed stupidity, when I think of Mpls Pub Schools.

As the son of two teachers, I can tell you that people show up at teachers' funerals and tell the family that their parents made huge differences in their lives.

It almost makes up for the fact that you watch your mother grade English papers almost every night while you grew up rahter than shopping, playing bridge, volunteering at church or spending time with her family like other people's moms did. Oh, and for earning near the bottom of the ranks for educated professionals. Oh, and for being insulted by the guy your mom is buying a new car from because he somehow sees teachers as parasites.

Interesting stuff, Beth, and I agree that “what it all means” requires a healthy dose of caution.

No matter what the research says, Richard Ingersoll is still relevant. In fact, as we come closer to identifying particular qualities that seem to lead to student growth and success, Ingersoll’s research (“Who Controls Teachers’ Work?”) may be even more important. We’re still dealing with a human being, as well as a process, whether the course or skills involve math, language, art, science or literacy, that is mostly beyond an individual teacher’s control, or even influence.

The key word is of course 'links'.
Correlation does not prove causation.
Until teachers and students are randomly assigned to schools and classes causation is too strong an inference.
The fact that students attending schools with certain characteristics have greater future earnings does not meaning that changing other schools to match those characteristics will cause their students to match the performance of those in the target schools.


I think the folks on the cutting edge of the reform discussion would agree with Ingersoll--and you!--that empowered teachers make for empowered learners and that that cycle of ownership drives authentic achievement and not just higher test scores. I've written a few stories about teacher-"owned" co-op schools, which are one example (not that you'd necessarily know it from those standardized test scores).

And I would point, in Google-able particular (yes--a new search engine is coming with the redesigned MinnPost!), to St. Paul's Dayton's Bluff, which I have also written about. The teachers there LOVE assessment data. They pore over it in teams and use it to help each other with strategies and practices.

All three of the gentlemen quoted in this story agreed that a) teaching to the test must stop; b) teaching to a better test will not be better; and c) we need help figuring out, on a more global scale, how to help all teachers.

I'm in the middle of reading Alfie Kohn's "Feel Bad Education," which really gets at the underlying intrinsic motivation gap. A school that stifles curiosity and creativity is bad for everyone, big and small.


Some random thoughts. Wonderful comments so far. #1 is especially disturbing. If the description is accurate, then obviously the teacher should be removed from the classroom - or more accurately, should never have been there in the first place. And this particular problem would not have been solved - in advance as it should have been - by testing.

I tend to agree with Beth that good teachers are happy - to a certain extent - to have external verification that they have, indeed, "gotten through" to their students by SOME kinds of standard exams. When I taught college chemistry, I used primarily my own exams. But at the end of the year, I always gave my students the American Chemical Society standardized exams to check my work. When I taught clinical chemistry, I also used my own exam questions. But I paid special attention to the results of my students on board exams, to make sure that they were competitive with students from other institutions. And gave them the third degree about what was on the exam and whether they thought they had been well prepared.

On the importance of the teacher-

Aside from the material, or shoving things down people's throats, there is another aspect that seems neglected in many of these discussions.

The attitude of a really good teacher to his or her students that "you can do this" is infectious and cannot be over-rated. Such support and encouragement is golden. Another factor is enthusiasm for the material - if the teacher is not interested, why should the students care? And the really good teachers never grow old in their enthusiasm for new material, new ways to teach, and pride in the accomplishments of their students. A good experienced teacher exudes confidence that he or she can teach the material, because they have done it before and know how.

Jeremy Powers nailed it. Teacher bashing is disgusting. And to do a really good job teaching takes a lot more time than most people realize.

I was talking to a woman the other day who teaches mid level courses in history, economics, and social studies. I asked her how much writing she had the students do. Quite a bit was her reply. Of course this comes out of her hide as she is the one who has to read the material and make comments on the writing and ideas.

Further discussion of this important topic - as stimulated by this excellent article - is crucial right now. The time for sound bites by politicians is past.

The research is interesting but only a piece of the puzzle and just because it is a measured piece doesn't make it the most important piece.

The math as simplified here leaves me a bit underwhelmed. The researchers unit of measurement is a class room and the period of time is lifetime earnings. Once you multiply 28 students by 30 years and divide it into $266,000 I'm not sure that the $300 additional earnings per year per student or .7% of per capita income is significant. I am sure the confidence level and interval are reported in the research but they aren't reported here.

It isn't clear that the effects are cumulative and there may be diminishing returns for additional years of good teaching.

There is no doubt that better teachers make smarter students I don't know that anyone needs this study to convince them of that. I'm also an economist, I love data and good research; but sometimes the research leaves me scratching my head at the profession. It reminds me of the old adage "when all you have is a hammer everything looks like a nail".

I don't know that this study was the best use of these researchers time. It seems more like publish or perish has run over real research needs at academic institutions.

If, by some miracle they could jump through all the hoops defenders of the status quo put up for reformers, the teacher's union would *still* stifle any attempt made to differentiate between great teachers and seat warmers.

To allow teachers to be identified and rewarded for exemplary, professional performance puts a stake in the heart of the socialist model all trade labor unions (which the NEA and AFT both are) depend on to maintain control over their membership.

Even if identifying great teachers were as simply transparent as comparing teachers who spend the bulk of their time on twitter against those who grade English papers almost every night, we’d be hearing excuses and exemptions from union bosses and their fellow travelers, whose function revolves around protecting the lowest common denominator at all costs.