Content Knowledge Is Important in Teaching

Everyone including teachers and parents are very busy nowadays. Both time and attention are at a premium. Headlines therefore matter. Seeing an article with a title that says, "Study: Improving Teachers' Math Knowledge Doesn't Boost Student Scores", can thus leave an impression that either content knowledge is unimportant in teaching, or studies on education are simply spurious. The truth is: Content knowledge matters in teaching and studies on education are not really fraudulent. Oftentimes, it is the title that is grossly misleading.

Above copied from Education Week's blog

The above article on Education Week talks about a study recently released by the Institute of Education Sciences (IES) entitled "Focusing on Mathematical Knowledge: The Impact of Content-Intensive Teacher Professional Development". The title of this study actually makes it clear that it is simply measuring the effect of a particular teacher professional development program. It is not encompassing enough to draw a general conclusion that how much a teacher knows does not affect learning. Knowledge matters. A previous study published in the American Educational Research Journal says so:

Effects of Teachers’ Mathematical Knowledge for Teaching on Student Achievement

  1. Deborah Loewenberg Ball
  1. University of Michigan


This study explored whether and how teachers’ mathematical knowledge for teaching contributes to gains in students’ mathematics achievement. The authors used a linear mixed-model methodology in which first and third graders’ mathematical achievement gains over a year were nested within teachers, who in turn were nested within schools. They found that teachers’ mathematical knowledge was significantly related to student achievement gains in both first and third grades after controlling for key student- and teacher-level covariates. This result, while consonant with findings from the educational production function literature, was obtained via a measure focusing on the specialized mathematical knowledge and skills used in teaching mathematics. This finding provides support for policy initiatives designed to improve students’ mathematics achievement by improving teachers’ mathematical knowledge.

Both studies involves thousands of students and hundreds of teachers yet what is being examined in each of these studies is distinct. The previous study simply looks at whether the content knowledge of teachers correlates with student's achievement. The recent study investigates whether a specific professional development program that includes Intel Math, Mathematics Learning Community, and Video Feedback Cycles has an effect on students' test scores. The details are important and, unfortunately, one does not get the full story without fully reading the article.  

Reading the above studies can actually provide important points regarding how enhancing teacher's content knowledge can impact students' learning outcomes. For example, the older study says, "Yet our results suggest that those who may benefit most are teachers in the lowest third of the distribution of knowledge, and that efforts to recruit teachers into professional development and pre-service coursework might focus most heavily on those with weak subject matter knowledge for teaching." Enhancing teacher's content knowledge works best with weak teachers. Beyond weak teachers, professional development aimed at improving teacher's knowledge needs to be targeted. And this is what the recent study shows: "The only teacher measure associated with student achievement was the Errors and Imprecision dimension, which was statistically significantly related to student achievement in the expected direction (estimate of association −0.20)." This dimension deals with:

  • Major mathematical errors (incorrect solution, incorrect definition, etc.) and/or Mathematical Content Errors allowing student errors to go uncorrected (except in cases where it is intentional).
  • Incorrect or imprecise use of mathematical symbols and mathematical terms.
  • Lack of Clarity in Presentation of mathematical tasks and unclear discussions or presentation of mathematical content.

Thus, it should not be surprising that the part of the intervention that targets specific problems in math instruction due to lack of content knowledge is found to have an impact. Misconceptions are real stumbling blocks in learning math in basic education. For interventions to be effective in raising students' math scores, these must address misconceptions held by students and teachers. As in the field of medicine, the intervention must come with an understanding of the problem so that the solution actually addresses the problem.