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Why all the fuss over value-added teacher data?

Good teachers matter and — as in every other profession — some are better than others. Researchers have even found that the very best teachers can help students overcome many of the effects of poverty and catch up to or surpass their more privileged peers.

That’s why there is intense interest now in finding better ways to judge the relative effectiveness of teachers. But how should that be done? Most teacher evaluations not only fail to single out successful teachers — they also don’t help principals determine which teachers need help to improve and which ones are failing their students altogether. Instead, all teachers end up being judged the same, which is to say, satisfactory.

“It’s universally acknowledged — teacher evaluations are broken,” said Timothy Daly, president of The New Teacher Project, a group that helps school districts recruit and train teachers.

Perhaps surprisingly, teacher-union leaders agree. Michael Mulgrew, president of New York City’s United Federation of Teachers (UFT), said last spring that “the current evaluation system doesn’t work for teachers — it’s too subjective, lacks specific criteria and is too dependent on the whims and prejudices of principals.”

So, it would seem that a system using student test scores to calculate how much “value” teachers add to their students’ learning would be fairer. Indeed, Mulgrew endorsed New York state’s new evaluation system, in which student achievement counts for 40 percent of a teacher’s rating.

“Value-added” measurements use complex statistical models to project a student’s future gains based on his or her past performance, taking into account how similar students perform. The idea is that good teachers add value by helping students progress further than expected, and bad teachers subtract value by slowing their students down.

Using value-added models to calculate teacher effectiveness wasn’t possible on a wide scale until recently. In the 1990s, William L. Sanders, a statistician at the University of Tennessee, pioneered the technique with student test scores — and managed to persuade the Hamilton County School Board to work with him in taking a closer look at the results.

The method — as Sanders puts it — is like measuring a child’s height on a wall. It tracks a child’s academic growth over the year, no matter how far ahead or behind the child was initially. Sanders discovered that teacher quality varied greatly in every school, and he and others also found that students assigned to good teachers for three consecutive years tended to make great strides, while those assigned to three poor ones in a row usually fell way behind.

Why value-added is hot now
Hundreds of districts, including Chicago, Denver, New York City and Washington, D.C., are using such methods as a way to strengthen their teacher evaluations by factoring in student performance. The biggest push for the use of such methods has come from the Obama administration, which insisted that states competing for grants under its $4.3 billion Race to the Top program find ways to link student performance to teacher evaluations. The dozen winners of those grants are now struggling to figure out how to do just that.

At the same time, however, value-added modeling is the focus of furious debate among scholars, policymakers, superintendents, education advocates and journalists.

In August, the Los Angeles Times was the subject of intense criticism and praise for its series that included value-added scores for individual teachers based on years of standardized test data — a project that newspapers in New York City now want to replicate. (Disclosure: The Los Angeles Times data-analysis was supported in part by a grant from The Hechinger Report.)

Read the Los Angeles Times package on value-added data for yourself.

The documentary Waiting for “Superman”, directed by Davis Guggenheim,also has thrust the teacher-evaluation issue into the national spotlight, highlighting as it does the historical disconnect between teacher job-security and student performance.

Limitations of value-added
Value-added models aren’t perfect, as even their most ardent supporters concede. Oft-cited shortcomings range from doubts about fairness to broader concerns centered on teaching goals.

“When people talk about their experience with a really good teacher, they’re not talking about test scores,” said Aaron Pallas, professor of sociology and education at Teachers College, Columbia University. “They’re talking about a teacher who gave them self-confidence, the ability to learn, an interest and curiosity about certain subjects.”

Critics point out that value-added data are only as good as the standardized tests — and test quality varies greatly from state to state. There are also many ways to calculate value-added scores, and different statistical techniques yield different results. The calculations may take into account factors that can affect achievement, such as class size, a school’s funding level and student demographics. Whether to include the race and poverty-status of students when measuring teachers is particularly contentious, writes Douglas N. Harris, an economist at the University of Wisconsin, Madison, in a report on value-added models released this week.

Whatever the computational method, a teacher’s score can vary significantly from one year to the next — results that could affect a teacher’s reputation and salary in places that are considering linking teacher pay to performance. And while value-added models may do a decent job of highlighting the best and worst performers, they’re widely considered unreliable in differentiating the good from the mediocre (or the mediocre from the terrible).

For this reason, many want value-added calculations only to be used in assessing schools and curricula — not individual teachers. But more and more, value-added data are playing a role in personnel decisions about bonuses, tenure and dismissal. In July, D.C. Schools Chancellor Michelle Rhee made waves by firing 165 teachers for poor evaluations, half of which depended on value-added data. With Adrian Fenty’s loss in the Democratic primary for mayor of D.C. last month, Rhee announced her resignation — but her teacher-evaluation system, IMPACT, will remain in place.

What lies ahead
Even those who champion value-added measures caution against using them as the sole means of evaluating teachers. Kate Walsh, president of the National Council on Teacher Quality, a research and advocacy group in Washington, D.C., has called value-added the best teacher-evaluation method so far. But she also says it would be a “huge mistake” to rely on it alone, or even primarily.

Randi Weingarten, president of the American Federation of Teachers, does not oppose the use of value-added data but wants to ensure evaluations are based on “classroom observations, self-evaluations, portfolios, appraisal of lesson plans, students’ written work” as well.

The best uses of value-added data may well be in the future. If educators could use the data to figure out what the most effective teachers are doing right and share that with colleagues, it would be a great boon. But while major foundation money is being spent to try and do just that, it is very difficult, especially given that great teachers often don’t know themselves what they’re doing right.

Whatever the future uses of value-added measures, the idea of holding teachers accountable for student performance seems here to stay.

“It’s a valuable part of the conversation,” said Daly, of The New Teacher Project. “It puts what matters most — student achievement — front and center as the most important responsibility for a teacher.”

Sarah Garland and Richard Lee Colvin contributed to this article, which first appeared in The Hechinger Report.

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Comments (2)

  1. Submitted by Gary Clements on 10/27/2010 - 02:26 pm.

    Before becoming a high school Media Specialist (Librarian…bought the books, taught research skills, ran the open computer lab and the Audio-Visual Department for the school), I was a junior high English teacher for 14 years. This in a metro suburban school of 1500 to 1800 students, and with class sizes in the 30s.

    Some of those years in the classroom, I was an All Star teacher, if judged by student test scores. Some of those years, I’d have gotten no raise, and perhaps been on the block for remedial action….but it was the same me, adjusted only for what was called for with a given group of students. What was vastly different was the character and ability of the student populations.

    “Value Added” evaluation of teachers is at BEST a very very tricky application, and at worst a worthless model that is swayed beyond veracity by the quality of the student groups. Positive student groups feed off each other in their behavior patterns and classroom atmosphere. So do negative student groups, when there are strong disruptive leaders in a given class, whose out of school lives come with them each day, and whose primary focus in school is to be disruptive. A whole class, over weeks of study, can be dragged upward or downward in their achievement by these positive or negative presences. And this can happen to any teacher…a very good one can be made to look mediocre, and a mediocre one can be made to look very good.

    No doubt an evaluation system based solely on rare visits and observances by a school administrator is also limited in its ability to see the real quality of a teacher. My experience leads me to observe that this is partly due to the vast range of quality in school administrators and their ability to see, judge fairly, communicate clearly, and work with staff in formative ways rather than only summative ways.

    It also strikes me that some of the main critics of teacher performance come from the business community at large, and the more politically conservative populace who supports business models. But I’d bet that there are few in the world of commerce who would care to be evaluated on their “Value Added” product when they have little or NO control over the quality of their raw material.
    Support your schools by checking each day with your children about their schoolwork, monitoring their grades, communicating with their teachers, and knowing what’s going on at school. Be involved. Read to young children. Make it a value of your OWN to be curious life-long learners, and model that value openly at home. Surround your family with reading material, thoughtful discussions and involvement rather than TV and video games. When the TV is on, balance the time spent on sports, sit coms, reality shows, and movies with time on such as PBS shows, The History Channel, Discovery Channel, Nature, and National Geographic Channel. This kind of family-school support will go further to impact your students’ achievement than anything else you as parents can do.
    Keep the Faith!

  2. Submitted by Richard Schulze on 10/27/2010 - 08:18 pm.

    The problem is that not having any substantial metrics has made the teaching profession susceptible to populist politicians.

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