Are veteran teachers more effective?
7/2/08
In New York City, as of 2008, teachers with 10 years' experience earn approximately 50% more than their brand-new colleagues. We assume this is because they are more effective at delivering to their students a superior education, as measured by improved abilities at reading and math, the two most important subjects in education. Importantly, this relationship should be clear even within similar demographics of students.
In this post I'd like to examine the effect that teacher experience has on students’ academic achievement in Mathematics and Reading in New York City public schools in District 85. Academic achievement should be measured by increases in standardized test scores in comparison with those of similar grades. This would control for the increase of test scores due merely to another year’s educational experience.
Teacher’s Experience is generally being defined as the number of complete years that a teacher has taught in a classroom setting at the applicable grade level, or one grade level higher or lower. However, there is typically some variance in the definition; however nonetheless the initial hypothesis should remain valid.
Teacher Efficacy would be measured via test scores in Reading and Math.
One would assume that there is a positive correlation between the years of teaching experience of the classroom teacher and the test score improvements of his or her students in the elementary schools in District 85 of New York City Public Schools. There are a number of confounding factors that would need to be controlled for, but positive correlation is nonetheless expected, particularly for the first five years of a teacher’s career. The correlation is expected to grow weaker as the teacher experience variable increases. Thus diminishing incremental or marginal returns from increases in teacher experience is expected. Additionally, Teacher Efficacy is being measured, in order to determine, if the hypothesis is supported by the study, whether Teacher Efficacy is positively correlated to teacher experience, and then
Research seems to provide compelling evidence that there is generally a positive correlation between teacher experience and academic achievement. Betts (1999), Grobler (2001), and Zuelke (2001) all found significantly positive benefit to teacher experience.
However, other studies have found little or no correlation between teacher experience and students’ academic achievement. Mulholland (1992) found there was a negative correlation between years of teacher experience and estimation of student achievement, which is an important component to student success. Although this correlation was not statistically significant, the fact that it was negative is still surprising. Herman (2001) found that teacher experience was “largely unrelated to student’s motivation to learn and class achievement.”
Betts (1999) conducted a study of over 5,000 undergraduates at University of California, San Diego, examining their high school characteristics and other data to statistically explain the factors that affect their Grade Point Average. Betts looked at two year’s worth of data from the university and combined it with data for California high schools, and used statistic techniques to develop the correlations among the variables.
Betts (1999) found a strong statistically significant correlation between average teacher experience and the student’s grade point average (GPA) in college. In fact according to the study, teacher experience was more significant than variables such as teacher’s highest degree and teacher/pupil ratio. This study may not be as relevant as necessary because there are a number of factors that differ between college level teaching and elementary school teaching. Betts voices an important concern, that in fact the causal arrows may be reversed, and that students with high GPAs (i.e., those from affluent areas, more academically motivated, or merely more intelligent) will attract more senior teachers, for a variety of reasons, including higher salary, better working conditions, etc.
“However, we did find a positive and significant link between teacher experience and the student’s GPA. We expressed concerns that this apparent relationship might reflect selection of teachers with seniority into job vacancies in the schools with the best prepared students, which are typically in more affluent areas. But two sets of robustness tests suggest that this sore of reverse causation in not at work.” (Betts 1999)
Mulholland (1992) examined 42 pairs of experienced and novice teachers and asked them to predict their pupils’ scores on reading and math tests. Teacher experience was used as a variable to measure the accuracy with which teachers can estimate students’ academic achievement.
Here surprisingly there was a negative correlation between years of teacher experience and estimation of student achievement. Although this correlation was not statistically significant, the fact that it was negative is still surprising, since estimation of a student’s future achievement is paramount in developing a relevant and applicable plan of study for the students.
Harris (2000) is an interesting survey that outlines a number of initiatives that may foster school improvement. Here we see that many of the benefits that experienced teachers enjoy, such as developing lessons, exercises and even curricula, are being ignored by larger programs that are highly prescriptive:
“The most effective school improvement programmes are characterized by the fact that they have instructional strategies that are highly prescriptive in the mode of delivery.” (Harris 2000).
This distinction is important because it will make the results of the inquiry more difficult to see. Since these new programs have been put into place, there is far less benefit to gaining experience with either more traditional teacher directed lessons and curricula, or even with other programs.
Grobler (2001) studied a random sample of black students in Grade 9 classes in South Africa, in order to find predictors of mathematics achievement. In total there were 174 students, 69 boys and 105 girls. Many variables were measured, including self-esteem (using the Rosenberg Self-Esteem Scale), raw scores on standardized tests, a socio-economic status questionnaire, teacher’s training, and of course experience. A standard multiple regression was then performed on each of the 14 variables. In this study Grobler (2001) found significant correlation between teacher’s experience and academic achievement for girl students, by not for boys. Interestingly, a Teaching Certificate had a greater positive impact on teaching success than having a full Degree in Education.
Zuelke (2001) conducted a study examining 257 6th grade students in suburban Chicago, to see which variables contributed most to students’ academic achievement, including teacher experience in grades 4 to 6. In other words, the authors wanted to only examine relevant teaching experience, and therefore only counted years of experience in similar grades. The study used multiple linear regression on the 122 variables collected. Their findings were clear: teaching experience was ranked second in importance in test score improvement. The most important indicator was of course the students’ pretest score.
In conclusion, there may be good reason that it has been difficult finding relevant research on what I initially believed to be a rather simple topic. There are a number of factors that would grossly distort any findings. More journal articles on the subject need to be located, or more research needs to be done.
If the results of the study support the original hypothesis that teaching experience has a positive impact on students’ academic achievement in Elementary Schools in District 85, there would be implications for teachers and administrators to examine the reasons for this phenomenon, despite the rigid teaching curricula and the highly prescriptive nature of the curriculum in District 85. The implication for this result would essentially be the reinforcement that teaching experience is an excellent indicator of a teacher’s ability and efficacy. It would be difficult to extract from this study a useful measure of the extent to which the experienced teachers are superior to the novice teachers, which would be an excellent extension of this study, and would provide a useful tool for administrators to determine the benefits of employing experienced teachers versus other methods for increasing student success, such as reducing class size. From an instructional perspective, if this hypothesis proves supported by the study, mentoring and co-teaching may be effective ways to increase teacher productivity.
However, if the results of the study fail to support the original hypothesis, there would be implications for more experienced teachers to examine other, less prescriptive, methods of teaching mathematics and literacy. Another major implication would be for administrators to question whether hiring experienced teachers is the most efficient use of funding.
The inclusion of Teacher Efficacy, as discussed before, is a method of finding investigating which factors specifically may account for any found difference in student achievement between the two Groups. While most literature concludes that Teacher Efficacy is positively correlated with Teacher Experience, this study does not assume this but rather includes this variable as an independent variable. If Teacher Efficacy is found to be positively correlated with Teacher Experience, this would imply that at least one of the factors that lead toward better teaching ability has been found and to some degree quantified. If Teacher Efficacy is found to be negatively correlated with Teacher Experience, this would imply that there must be other more important factor that would cause experienced teachers to improve student academic achievement over the less experienced teachers.
Further research could be done on further dividing teacher experience into more “buckets”, and extending the scope of the study to include brand new teachers and teachers with as much as 30 year’s experience.
It is important to mention the limitations of the study, especially with regard to the schools in which this study was performed. There are three factors in particular that limit the applicability of this study:
1) Location: As mentioned previously, the schools in this study are located in areas with high crime, a large proportion of minorities and ELL students, and relative poverty.
2) The prescriptive nature of the measuring tests: As noted earlier, SFA and Trailblazers are highly prescriptive, and there is little ability to vary the lessons. This obviously penalizes experienced teacher who have found alternative methods of assessment and instruction.
3) The non diverse nature of the assessment: There were essentially only two methods of assessment in this study, and therefore there may be a risk that the results lack some level of validity.
In the future, other researchers may want to improve upon this study by introducing other, more subjective variables to better examine more precisely the components of “teacher experience” that improve student achievement. Also, it would be valuable to understand what would happen if this study were to be adapted and conducted in other more wealthy Districts throughout New York City, even those that do not use SFA or Trailblazers, or in other cities with a similar population and demographic profiles.
The results of this study appear to confirm the results that were found in Betts (1999), Grobler (2001), and Zuelke (2001), which all found a positive correlation between teacher experience and academic achievement. This study contradicts the results found in Mulholland (1992), where there was a negative (albeit not statistically significant) correlation between a teacher’s years of experience and his or her ability to estimate student achievement.