Teacher Effectiveness Measures: The Tortoise and the Hare

Several recent initiatives have fueled a firestorm of debate around measuring the effectiveness of our teachers. In the competition for billions of dollars through both Race to the Top and the Teacher Incentive Fund, responding states and districts were required to propose measures of teacher effectiveness that incorporate student growth data. Most of the applicants that were awarded these funds proposed weighting student data up to 50% within the measure. In an effort to increase teacher accountability, high stakes have been proposed for these effectiveness measures. They may be used to make decisions related to employment, like promotions and dismissals, as well as monetary bonuses.

In my opinion, there have been two kinds of responses to these teacher effectiveness measures. First, there’s been what I classify as the “sidelines” response where some researchers and teachers simply don’t want to take part in the development of these measures. Researchers claim that the value-added models that have been proposed to estimate teacher effects based on student data are flawed, whereas teachers claim that their work cannot be accurately and fairly reflected by student test scores alone. While these points are legitimate, those on the sidelines don’t tend to suggest alternative solutions.

In stark contrast to the sidelines response, there is also the response that I liken to the hare from the famous fable. Some policy-makers and vendors have ignored the debates and taken off in the race to provide a solution to teacher effectiveness. By moving directly to implementation of such measures, the policy-makers claim they will encourage reform within schools, and the vendors are happy to accept the new business.

I have followed both responses for nearly a year. Initially, I fell in line with many colleagues and wanted no part of using statistical models and student data to produce estimates of teacher effectiveness. I am now resigned to the fact that the sidelines response is unproductive. Refusing to participate does not impact the inevitability of teacher effectiveness measures and can be seen as a refusal to contribute to a solution.

So now that I’m ready to step off the sidelines and engage in teacher effectiveness measures, I realize that those who chose the hare response are so far ahead that they are no longer visible on the horizon. But perhaps they have paused to take a nap. By producing a solution to teacher effectiveness so quickly, perhaps this group has failed to provide the research and documentation needed to support and sustain such measures. Likely, they did not engage stakeholders to elicit feedback about what effective teaching really means. There has not been time to conduct validity studies that empirically link their measure to results in the classroom. While the hares in our industry may have gotten off to the fastest start when it comes to teacher effectiveness, I suspect that their lead will not last.

I suggest that neither the sidelines nor the sprint are advisable. Rather I advocate for what could be called the tortoise approach. It’s not a quick-fix solution, but with more time, a valuable and defensible measure of teacher effectiveness can be defined and established.


I suggest we tortoises follow comparable steps and standards to those used for assessment development:

• The first step could be similar to a content review, where stakeholders convene to discuss and identify the essential components of teacher effectiveness.


• Then content experts can partner with psychometricians to design and refine measures of these essential components.


• Next, the measures could be piloted and validity studies could be performed. Standard setting could be used to establish the line that divides effective from ineffective teaching.


• Custom reports could compare individual teacher performance to that of the schools’ teachers or teachers with similar student populations.


• Professional development activities could be offered to help schools improve the skills of lower performing teachers.

Each of these steps takes time but also provides essential information needed to develop a valid and useful measure of teacher effectiveness.

Without sufficient evidence to support the defensibility and validity of the hares’ quick-fix solutions to teacher effectiveness, I wonder if they will even reach the halfway point, let alone the finish line. In contrast, we tortoises can continue to move forward building measures with known procedures, valuable stakeholder input, and informative data analysis. Let’s heed the advice of The Tortoise and the Hare and work to establish a quality measure of teacher effectiveness rather than the fastest solution.

Tracey Magda
Psychometrician
Evaluation Systems
Assessment & Information
Pearson