In a previous post, I discussed the initial results from new teacher evaluations in several states, and the fact that states with implausibly large proportions of teachers in the higher categories face a difficult situation – achieving greater differentiation while improving the quality and legitimacy of their systems.
I also expressed concern that pre-existing beliefs about the “proper” distribution of teacher ratings — in particular, how many teachers should receive the lowest ratings — might inappropriately influence the process of adjusting the systems based on the first round of results. In other words, there is a risk that states and districts will change their systems in a crude manner that lowers ratings simply for the sake of lowering ratings.
Such concerns of course imply a more general question: How should we assess the results of new evaluation systems? That’s a complicated issue, and these are largely uncharted waters. Nevertheless, I’d like to offer a few thoughts as states and districts move forward. Read More »
A correlation between two variables measures the strength of the linear relationship between them. Put simply, two variables are positively correlated to the extent that individuals with relatively high or low values on one measure tend to have relatively high or low values on the other, and negatively correlated to the extent that high values on one measure are associated with low values on the other.
Correlations are used frequently in the debate about teacher evaluations. For example, researchers might assess the relationship between classroom observations and value-added measures, which is one of the simpler ways to gather information about the “validity” of one or the other – i.e., whether it is telling us what we want to know. In this case, if teachers with higher observation scores also tend to get higher value-added scores, this might be interpreted as a sign that both are capturing, at least to some extent, “true” teacher performance.
Yet there seems to be a tendency among some advocates and policy makers to get a little overeager when interpreting correlations. Read More »
** Reprinted here
in the Washington Post
The following is written by Morgan S. Polikoff and Matthew Di Carlo. Morgan is Assistant Professor in the Rossier School of Education at the University of Southern California.
One of the primary policy levers now being employed in states and districts nationwide is teacher evaluation reform. Well-designed evaluations, which should include measures that capture both teacher practice and student learning, have great potential to inform and improve the performance of teachers and, thus, students. Furthermore, most everyone agrees that the previous systems were largely pro forma, failed to provide useful feedback, and needed replacement.
The attitude among many policymakers and advocates is that we must implement these systems and begin using them rapidly for decisions about teachers, while design flaws can be fixed later. Such urgency is undoubtedly influenced by the history of slow, incremental progress in education policy. However, we believe this attitude to be imprudent. Read More »
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 »