One can often hear opponents of value-added referring to these methods as “junk science.” The term is meant to express the argument that value-added is unreliable and/or invalid, and that its scientific “façade” is without merit.
Now, I personally am not opposed to using these estimates in evaluations and other personnel policies, but I certainly understand opponents’ skepticism. For one thing, there are some states and districts in which design and implementation has been somewhat careless, and, in these situations, I very much share the skepticism. Moreover, the common argument that evaluations, in order to be “meaningful,” must consist of value-added measures in a heavily-weighted role (e.g., 45-50 percent) is, in my view, unsupportable.
All that said, calling value-added “junk science” completely obscures the important issues. The real questions here are less about the merits of the models per se than how they’re being used. Read More »
Controversial proposals for new teacher evaluation systems have generated a tremendous amount of misinformation. It has come from both “sides,” ranging from minor misunderstandings to gross inaccuracies. Ostensibly to address some of these misconceptions, the advocacy group Students First (SF) recently released a “myth/fact sheet” on evaluations.
Despite the need for oversimplification inherent in “myth/fact” sheets, the genre can be useful, especially about topics such as evaluation, about which there is much confusion. When advocacy groups produce them, however, the myths and facts sometimes take the form of “arguments we don’t like versus arguments we do like.”
This SF document falls into that trap. In fact, several of its claims are a little shocking. I would still like to discuss the sheet, not because I enjoy picking apart the work of others (I don’t), but rather because I think elements of both the “myths” and “facts” in this sheet could be recast as “dual myths” in a new sheet. That is, this document helps to illustrate how, in many of our most heated education debates, the polar opposite viewpoints that receive the most attention are often both incorrect, or at least severely overstated, and usually serve to preclude more productive, nuanced discussions.
Let’s take all four of SF’s “myth/fact” combinations in turn. Read More »
In a story for Education Week, always reliable Stephen Sawchuk reports on what may be a trend in states’ first results from their new teacher evaluation systems: The ratings are skewed toward the top.
For example, the article notes that, in Michigan, Florida and Georgia, a high proportion of teachers (more than 90 percent) received one of the two top ratings (out of four or five). This has led to some grumbling among advocates and others, citing similarities between these results and those of the old systems, in which the vast majority of teachers were rated “satisfactory,” and very few were found to be “unsatisfactory.”
Differentiation is very important in teacher evaluations – it’s kind of the whole point. Thus, it’s a problem when ratings are too heavily concentrated toward one end of the distribution. However, as Aaron Pallas points out, these important conversations about evaluation results sometimes seem less focused on good measurement or even the spread of teachers across categories than on the narrower question of how many teachers end up with the lowest rating – i.e., how many teachers will be fired.
Read More »
Some Florida officials are still having trouble understanding why they’re finding no relationship between the grades schools receive and the evaluation ratings of teachers in those schools. For his part, new Florida education Commissioner Tony Bennett is also concerned. According to the article linked above, he acknowledges (to his credit) that the two measures are different, but is also considering “revis[ing] the models to get some fidelity between the two rankings.”
This may be turning into a potentially risky situation. As discussed in a recent post, it is important to examine the results of the new teacher evaluations, but there is no reason one would expect to find a strong relationship between these ratings and the school grades, as they are in large part measuring different things (and imprecisely at that). The school grades are mostly (but not entirely) driven by how highly students score, whereas teacher evaluations are, to the degree possible, designed to be independent of these absolute performance levels. Florida cannot validate one system using the other.
However, as also mentioned in that post, this is not to say that there should be no relationship at all. For example, both systems include growth-oriented measures (albeit using very different approaches). In addition, schools with lower average performance levels sometimes have trouble recruiting and retaining good teachers. Due to these and other factors, the reasonable expectation is to find some association overall, just not one that’s extremely strong. And that’s basically what one finds, even using the same set of results upon which the claims that there is no relationship are based.
Read More »
Our guest author today is David B. Cohen, a National Board Certified high school English teacher in Palo Alto, CA, and the associate director of Accomplished California Teachers (ACT). His blog is at InterACT.
As we settle into 2013, I find myself increasingly optimistic about the future of the teaching profession. There are battles ahead, debates to be had and elections to be contested, but, as Sam Cooke sang, “A change is gonna come.”
The change that I’m most excited about is the potential for a shift towards teacher leadership in schools and school systems. I’m not naive enough to believe it will be a linear or rapid shift, but I’m confident in the long-term growth of teacher leadership because it provides a common ground for stakeholders to achieve their goals, because it’s replicable and scalable, and because it’s working already.
Much of my understanding of school improvement comes from my teaching career – now approaching two decades in the classroom, mostly in public high schools. However, until six years ago, I hadn’t seen teachers putting forth a compelling argument about how we might begin to transform our profession. A key transition for me was reading a Teacher Solutions report from the Center for Teaching Quality (CTQ). That 2007 report, Performance-Pay for Teachers: Designing a System that Students Deserve, showed how the concept of performance pay could be modified and improved upon with better definitions of a variety of performance, and differentiated pay based on differentiated professional practice, rather than arbitrary test score targets. I ended up joining the CTQ Teacher Leaders Network the same year, and have had the opportunity ever since to learn from exceptional teachers from around the country. Read More »
Our guest author today is Douglas N. Harris, associate professor of economics and University Endowed Chair in Public Education at Tulane University in New Orleans. His latest book, Value-Added Measures in Education, provides an accessible review of the technical and practical issues surrounding these models.
This past November, I wrote a post for this blog about shifting course in the teacher evaluation movement and using value-added as a “screening device.” This means that the measures would be used: (1) to help identify teachers who might be struggling and for whom additional classroom observations (and perhaps other information) should be gathered; and (2) to identify classroom observers who might not be doing an effective job.
Screening takes advantage of the low cost of value-added and the fact that the estimates are more accurate in making general assessments of performance patterns across teachers, while avoiding the weaknesses of value-added—especially that the measures are often inaccurate for individual teachers, as well as confusing and not very credible among teachers when used for high-stakes decisions.
I want to thank the many people who responded to the first post. There were three main camps. Read More »
Last week, Florida State Senate President Don Gaetz (R – Niceville) expressed his skepticism about the recently-released results of the state’s new teacher evaluation system. The senator was particularly concerned about his comparison of the ratings with schools’ “A-F” grades. He noted, “If you have a C school, 90 percent of the teachers in a C school can’t be highly effective. That doesn’t make sense.”
There’s an important discussion to be had about the results of both the school and teacher evaluation systems, and the distributions of the ratings can definitely be part of that discussion (even if this issue is sometimes approached in a superficial manner). However, arguing that we can validate Florida’s teacher evaluations using its school grades, or vice-versa, suggests little understanding of either. Actually, given the design of both systems, finding a modest or even weak association between them would make pretty good sense.
In order to understand why, there are two facts to consider. Read More »
One of the most frequent criticisms of value-added and other growth models is that they are “unstable” (or, more accurately, modestly stable). For instance, a teacher who is rated highly in one year might very well score toward the middle of the distribution – or even lower – in the next year (see here, here and here, or this accessible review).
Some of this year-to-year variation is “real.” A teacher might get better over the course of a year, or might have a personal problem that impedes their job performance. In addition, there could be changes in educational circumstances that are not captured by the models – e.g., a change in school leadership, new instructional policies, etc. However, a great deal of the the recorded variation is actually due to sampling error, or idiosyncrasies in student testing performance. In other words, there is a lot of “purely statistical” imprecision in any given year, and so the scores don’t always “match up” so well between years. As a result, value-added critics, including many teachers, argue that it’s not only unfair to use such error-prone measures for any decisions, but that it’s also bad policy, since we might reward or punish teachers based on estimates that could be completely different the next year.
The concerns underlying these arguments are well-founded (and, often, casually dismissed by supporters and policymakers). At the same time, however, there are a few points about the stability of value-added (or lack thereof) that are frequently ignored or downplayed in our public discourse. All of them are pretty basic and have been noted many times elsewhere, but it might be useful to discuss them very briefly. Three in particular stand out. Read More »
** Reprinted here in the Washington Post
2012 was another busy year for market-based education reform. The rapid proliferation of charter schools continued, while states and districts went about the hard work of designing and implementing new teacher evaluations that incorporate student testing data, and, in many cases, performance pay programs to go along with them.
As in previous years (see our 2010 and 2011 reviews), much of the research on these three “core areas” – merit pay, charter schools, and the use of value-added and other growth models in teacher evaluations – appeared rather responsive to the direction of policy making, but could not always keep up with its breakneck pace.*
Some lag time is inevitable, not only because good research takes time, but also because there’s a degree to which you have to try things before you can see how they work. Nevertheless, what we don’t know about these policies far exceeds what we know, and, given the sheer scope and rapid pace of reforms over the past few years, one cannot help but get the occasional “flying blind” feeling. Moreover, as is often the case, the only unsupportable position is certainty. Read More »
The New Teacher Project’s (TNTP) recent report on teacher retention, called “The Irreplaceables,” garnered quite a bit of media attention. In a discussion of this report, I argued, among other things, that the label “irreplaceable” is a highly exaggerated way of describing their definitions, which, by the way, varied between the five districts included in the analysis. In general, TNTP’s definitions are better-described as “probably above average in at least one subject” (and this distinction matters for how one interprets the results).
I’d like to elaborate a bit on this issue – that is, how to categorize teachers’ growth model estimates, which one might do, for example, when incorporating them into a final evaluation score. This choice, which receives virtually no discussion in TNTP’s report, is always a judgment call to some degree, but it’s an important one for accountability policies. Many states and districts are drawing those very lines between teachers (and schools), and attaching consequences and rewards to the outcomes.
Let’s take a very quick look, using the publicly-released 2010 “teacher data reports” from New York City (there are details about the data in the first footnote*). Keep in mind that these are just value-added estimates, and are thus, at best, incomplete measures of the performance of teachers (however, importantly, the discussion below is not specific to growth models; it can apply to many different types of performance measures). Read More »
** Reprinted here in the Washington Post
Our guest author today is Douglas N. Harris, associate professor of economics and University Endowed Chair in Public Education at Tulane University in New Orleans. His latest book, Value-Added Measures in Education, provides an excellent, accessible review of the technical and practical issues surrounding these models.
Now that the election is over, the Obama Administration and policymakers nationally can return to governing. Of all the education-related decisions that have to be made, the future of teacher evaluation has to be front and center.
In particular, how should “value-added” measures be used in teacher evaluation? President Obama’s Race to the Top initiative expanded the use of these measures, which attempt to identify how much each teacher contributes to student test scores. In doing so, the initiative embraced and expanded the controversial reliance on standardized tests that started under President Bush’s No Child Left Behind.
In many respects, The Race was well designed. It addresses an important problem – the vast majority of teachers report receiving limited quality feedback on instruction. As a competitive grants program, it was voluntary for states to participate (though involuntary for many districts within those states). The Administration also smartly embraced the idea of multiple measures of teacher performance.
But they also made one decision that I think was a mistake. They encouraged—or required, depending on your vantage point—states to lump value-added or other growth model estimates together with other measures. The raging debate since then has been over what percentage of teachers’ final ratings should be given to value-added versus the other measures. I believe there is a better way to approach this issue, one that focuses on teacher evaluations not as a measure, but rather as a process. Read More »
People often ask me for my “bottom line” on using value-added (or other growth model) estimates in teacher evaluations. I’ve written on this topic many times, and while I have in fact given my overall opinion a couple of times, I have avoided expressing it in a strong “yes or no” format. There’s a reason for this, and I thought maybe I would write a short piece and explain myself.
My first reaction to the queries about where I stand on value-added is a shot of appreciation that people are interested in my views, followed quickly by an acute rush of humility and reticence. I know think tank people aren’t supposed to say things like this, but when it comes to sweeping, big picture conclusions about the design of new evaluations, I’m not sure my personal opinion is particularly important.
Frankly, given the importance of how people on the ground respond to these types of policies, as well as, of course, their knowledge of how schools operate, I would be more interested in the views of experienced, well-informed teachers and administrators than my own. And I am frequently taken aback by the unadulterated certainty I hear coming from advocates and others about this completely untested policy. That’s why I tend to focus on aspects such as design details and explaining the research – these are things I feel qualified to discuss. (I also, by the way, acknowledge that it’s very easy for me to play armchair policy general when it’s not my job or working conditions that might be on the line.)
That said, here’s my general viewpoint, in two parts. First, my sense, based on the available evidence, is that value-added should be given a try in new teacher evaluations. Read More »
One of the most important things in education policy to keep an eye on is the first round of changes to new teacher evaluation systems. Given all the moving parts and the lack of evidence on how these systems should be designed and their impact, course adjustments along the way are not just inevitable, but absolutely essential.
Changes might be guided by different types of evidence, such as feedback from teachers and administrators or analysis of ratings data. And, of course, human judgment will play a big role. One thing that states and districts should not be doing, however, is assessing their new systems – or making changes to them – based whether or not raw overall test scores go up or down within the first few years.
Here’s a little reality check: Even the best-designed, best-implemented new evaluations are unlikely to have an immediate measurable impact on aggregate student performance. Evaluations are an investment, not a quick fix. And they are not risk-free. Their effects will depend on the quality of systems, how current teachers and administrators react to them and how all of this shapes and plays out in the teacher labor market. As I’ve said before, the realistic expectation for overall performance – and this is no guarantee – is that there will be some very small, gradual improvements, unfolding over a period of years and decades.
States and districts that expect anything more risk making poor decisions during these crucial, early phases. Read More »
D.C. Public Schools (DCPS) recently announced a few significant changes to its teacher evaluation system (called IMPACT), including the alteration of its test-based components, the creation of a new performance category (“developing”), and a few tweaks to the observational component (discussed below). These changes will be effective starting this year.
As with any new evaluation system, a period of adjustment and revision should be expected and encouraged (though it might be preferable if the first round of changes occurs during a phase-in period, prior to stakes becoming attached). Yet, despite all the attention given to the IMPACT system over the past few years, these new changes have not been discussed much beyond a few quick news articles.
I think that’s unfortunate: DCPS is an early adopter of the “new breed” of teacher evaluation policies being rolled out across the nation, and any adjustments to IMPACT’s design – presumably based on results and feedback – could provide valuable lessons for states and districts in earlier phases of the process.
Accordingly, I thought I would take a quick look at three of these changes. Read More »
A while back, I noted that states and districts should exercise caution in assigning weights (importance) to the components of their teacher evaluation systems before they know what the other components will be. For example, most states that have mandated new evaluation systems have specified that growth model estimates count for a certain proportion (usually 40-50 percent) of teachers’ final scores (at least those in tested grades/subjects), but it’s critical to note that the actual importance of these components will depend in no small part on what else is included in the total evaluation, and how it’s incorporated into the system.
In slightly technical terms, this distinction is between nominal weights (the percentage assigned) and effective weights (the percentage that actually ends up being the case). Consider an extreme hypothetical example – let’s say a district implements an evaluation system in which half the final score is value-added and half is observations. But let’s also say that every teacher gets the same observation score. In this case, even though the assigned (nominal) weight for value-added is 50 percent, the actual importance (effective weight) will be 100 percent, since every teacher receives the same observation score, and so all the variation between teachers’ final scores will be determined by the value-added component.
This issue of nominal/versus effective weights is very important, and, with exceptions, it gets almost no attention. And it’s not just important in teacher evaluations. It’s also relevant to states’ school/district grading systems. So, I think it would be useful to quickly illustrate this concept in the context of Florida’s new district grading system. Read More »
