Prospective Elementary Mathematics Teacher Content Knowledge: What Do We Know, What Do We Not Know, and Where Do We Go?

IntroductionThe collection of papers in this Special Issue is the result of a PME-NA Working Group titled "Preservice Elementary School Teachers' Content Knowledge in Mathematics" (Thanheiser et al., 2009; Thanheiser et al., 2010; Thanheiser, Lo, Kastberg, Canda, & Eddy, 2007} that met three times (2007, 2009, and 2010} and continued to collaborate after those years. All of the authors of this volume are mathematics educators teaching content and methods courses to prospective elementary teachers (PTs} and are involved in research related to PTs' content knowledge in various content areas. The goal of the group was to provide a summary of the research (as of 2012} conducted on PTs' mathematical content knowledge needed for teaching and to inform the research community on (a} what we currently know, (b} what we do not know yet, and (c} what we need to know.The collection of papers in this Special Issue represents a summary of PTs' mathematical content knowledge for teaching mathematics to children up to age 14 (see the Common Core State Standards [CCSS], National Governors Association Center for Best Practices, Council of Chief State School Officers, 2010}, with emphasis on number and operations (treated in three papers: whole numbers, fractions, and decimals}, geometry and measurement, and algebra. For each of these listed areas, an individual paper summarizes the current state of the research literature. The papers provide an insight into areas well researched (e.g., division of fractions} and areas that need more work (e.g., fraction number sense} to round out our understanding of PTs' mathematical content knowledge for teaching.This final paper of the Special Issue is based on a focused collection of findings spanning across the five content area papers. We acknowledge that it provides a somewhat incomplete perspective on what we know about PTs' content knowledge and development due to the following limitations: (a] the exclusion of mathematics outside the scope of our Working Group, (b] the exclusion of Standards of Mathematical Practice, and (c] the limitations of the methodology of the Working Group (described in the introduction of this Special Issue].Descriptive Themes of the Summarized Research: Counts and TypesIn this Special Issue, we summarized a total of 112 peer-reviewed research articles published in journals reporting on prospective teachers' content knowledge, spanning the years 1978 to 2012. We categorized the research articles into three sections: A Historical Look (pre 1998], A Current Perspective (1998-2011], and A View of the Horizon (20112012]. We incorporated a review of an additional 18 papers published in PME and PME-NA conference proceedings in the years 2011 and 2012 to allow us to see what is on the horizon; however, those 18 papers are not included in the summary totals we are reporting in this section as they are conference papers and did not appear in peer reviewed journals. Thus, the total numbers reported in this section refer to peer-reviewed research articles from journals.Number of Research Articles Published Increased Over TimeThe number of published research articles across the content areas can be seen in Table 1. Before 1998, we found a total of 38 research articles focusing on PTs' content knowledge; the number increased to 68 in the timespan from 1998 to 2011. The count of published research articles for 2012 suggests a decline in research on mathematical content knowledge of PTs; however, if we include the counts of papers from the proceedings (parenthetical counts in the table],18 the View of the Horizon promises a possible increase in publications for the next decade. Across two of the three time periods, we note that the content area of fractions has the highest frequency of publications, suggesting perhaps that the challenges faced when PTs are learning fraction content prompts more research attention. When we view the counts by individual years (see Figure 1], we see that 1989 marks an increase in research focused on PTs' content knowledge, followed by a second increase in 2007. …