We all want our children to be successful in school. There are many different factors that influence children’s success in education, and recently much of the attention in politics and in the media has turned to the influence of individual teachers on students’ success. Most of this attention centers around teacher effectiveness, and there is a huge debate about whether teachers should be receiving bonuses for being effective or even have their pay determined based on their effectiveness. Now that our kids are back in school, you might be wondering how effective your child’s teacher is. How would you know?
An article was published recently in the Los Angeles Times about teacher effectiveness and possible ways to measure how effective teachers are. One way of measuring teacher effectiveness that has become increasingly popular is called “value-added analysis.” It works like this: say you have two teachers, Ms. Doe and Ms. Jones. At the beginning of the school year they look at the test scores of the children in Ms. Doe’s class, and at the test scores in Ms. Jones’ class, and they look at the percentile ranks of the students in each class. Then at the end of the school year you compare: are the students still at the same percentile rank? Or did they go up or down in their percentile rank? The idea is that, if students in Ms. Jones’ class go up in percentile rank while students in Ms. Doe’s class go down in percentile rank, then this means that Ms. Jones is a more effective teacher than Ms. Doe. At first glance this approach seems to make sense: the percentile rank of children’s scores at the end of the year are compared to the percentile rank of their own scores at the beginning of the year. The teacher whose students moved up the most in percentile rank is considered to be the most effective teacher. The thought is that if the most effective teachers are rewarded (through bonuses) and the least effective teachers are fired, education as a whole will become much better.
The problem with a value-added analysis is that it is comparing apples to oranges. It is very difficult to compare teachers in one school to another, let alone teachers from one school district to another. Moreover, it is much easier for a teacher in a low performing school to help move students from below average to average on standardized tests than it is for a teacher in a high performing school to help students move from very high to…very, very high.
In my opinion, perhaps an even bigger problem is that an “effective” teacher who helps students become “successful” cannot simply be defined in terms of performance on standardized tests. Is that all that it means to be a successful as a student…as a person? To perform well on standardized tests?!?
I think a better approach to promoting teacher effectiveness would start by broadening our definition about what it means to be “successful” in school beyond scores on standardized tests. For example, do students learn to: think critically, solve problems independently, and think outside the box? Is their natural curiosity being fostered? Does the teacher recognize and build on students’ strengths, while providing them support to grow in areas of weakness? Is there a warm, supportive, and respectful community climate in the classroom? Do students learn to be good citizens, are they sensitive and respectful to the needs of others, do they learn to take responsibility? Are they being prepared to be successful beyond high school, in college and/or in a profession? These as well as many other factors are part of a “successful” education and cannot be measured through standardized test scores alone.
Perhaps a better approach would be to determine what qualities effective teachers have in common. A good example of such research is the work of Dr. Robert Pianta, whose work is also briefly described in The New Yorker. Among other things, Dr. Pianta found that effective teachers have a keen eye for each of their students’ accomplishment and needs, and they are able to provide individualized support to each student according to their needs. I will go into further detail about this in a future post. My point is that if we determine the qualities that make teachers effective, we should be focusing on providing support to experienced teachers, beginning teachers, and teachers in training alike to foster these qualities.
Because there are so many different factors that influence students’ effectiveness in school, I will be devoting a series of blogs about some of these factors over the coming weeks. Teachers are an important part of this equation, but there are many other important factors as well, including things parents can do at home. I am looking forward to exploring these with you.
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I agree that the definition of an effective teacher needs to somehow be broadened; however how are you going to be able to compare teachers based on subjective analysis? Since value-added analysis initially compares every teachers performance based upon their own student’s academic growth before comparing them to other teachers, I think this is a rather accurate and fair approach. Your point about lower performing students not improving as easily as higher performing students is probably valid however. Perhaps exceptions need to be made in some cases by comparing teachers who have similar baseline scores to each other. Good article
Dear Mr. Boggess,
Thank you for sending your comment. I agree that it is not yet clear how to measure teacher’s effectiveness, since we do not yet have a definition of “effectiveness” that covers the whole spectrum of what makes teachers effective. I think Dr. Pianta’s research is very valuable to get us closer to this point.
The problem I have with value added analysis is that it uses percentile ranks, and changes in percentile rank to determine teacher effectiveness (based on standardized test scores only), and to compare teachers to one another. A percentile rank is a measure of how someone performed relative to everybody else; on a standardized test, you would look at how one student performed relative to all other students in their grade level in the entire school district. So if someone’s score is at the 64th percentile, this means that their score is better than the scores of 64 percent of students at their grade level.
Percentile ranks are not absolute scores, because the percentile rank that is tied to a particular score depends on the scores of everybody else. So if Johnny scores a 70 on his spelling test, he might be in the 50th percentile in school district A, and at the 85th percentile in school district B. Another feature of percentile ranks is that they cluster in the middle and spread out at the extremes (think of the famous “bell curve”). Most students score in the average range, so if Johnny’s score of 70 is at the 50th percentile in district A, and at the end of the year he scores an 80, his percentile rank may have gone up from 50 to 64. However, if this same score of 70 was at the 85th percentile in district B, and his score went up to 80 at the end of the year, his percentile rank may have only gone up to 86. The same absolute gain in points (10 points) leads to a 14 point gain in percentile rank in school district A, but only 1 point gain in percentile rank in school district B.
If you have teachers with students whose scores are mostly in the average range on standardized tests, you will likely see much more fluctuation in percentile ranks. On the other hand, when a teacher has a class of students who score really high, you will probably not see as much fluctuation in percentile ranks, simply because there are generally fewer students who score really high, because most students score around average. Therefore, if you have a group of really high scoring students, it will be much more difficult to actually make gains in percentile rank. In fact, it is much more likely to see drops in percentile rank at the high scores because of a statistical phenomena called “regression to the mean”. One could then erroneously conclude that teachers who happen to be teaching high achieving students are not very effective, because you wouldn’t see as many gains in percentile points.
This is why I have a problem using percentile ranks to base very important and far reaching decisions on about who is effective or ineffective, and who should keep or lose their job or receive a bonus. Because most people don’t understand how percentile ranks work, many people erroneously regard percentile ranks as absolute scores.
I hope this helps to clarify why I don’t think value added analysis is a fair approach.
Thank you again for your comment, and I hope you will keep reading my blog!
Iektje
[...] couple of weeks ago I posted a blog about measuring teacher effectiveness. While I was writing this blog, I reflected on how many [...]