1 Introduction

The development of a scientific journal is an ongoing challenge for editors and members of the editorial board. Adapting the journal’s scope and goals of the journal, increasing the quality of submissions, and improving the review process are essential aspects of the development process. Among the editors’ most important tasks is that of monitoring how the field changes over time. Given that ZDM - Mathematics Education is an invitation-only journal, its editors must constantly search for topics that are likely to be of interest to the scientific community. An essential part of this work involves monitoring changes in the field; identifying trends in development; and analyzing which topics are underrepresented in research, which topics have developed dynamically in recent years and require updating, and which topics have emerged recently. These considerations are embedded in the world’s social, economic, and political developments. This monitoring of recent changes in the field has led to the introduction of a new category of special issues, focusing specifically on “Reviews of Important Themes in Mathematics Education.” In this editorial, we shall explain the origins of this idea and the challenges and opportunities we ascribe to this new line of special issues.

2 The importance of reviews in scientific disciplines

Mathematics educators are obliged to negotiate the ever-increasing number of scientific studies in mathematics education that generate new knowledge for researchers, teachers, and policy makers. This is no easy task, and finding and systematizing relevant information are major challenges of our time. Search engines such as Google combined with artificial intelligence function as tools that assist educators in overcoming these challenges and enhancing the efficiency of scientific work in the future.

Original empirical or theoretical contributions published in scientific journals (i.e., “primary” studies) serve as the foundation for future systematization. They form the basis of research, and as such, studies of this nature are crucial for scientific progress. The high-quality reviews of existing literature that empirical or theoretical contributions typically include offer insights into the state of the field and should provide a micro synthesis of the relevant research area. However, these literature reviews also have limitations. In empirical or theoretical papers, we often expect the authors to provide a focused overview of the topic of interest. The literature reviewed should be neither too broad nor too narrow, and it should be related to the formulated research questions. However, the accumulation of research on a given topic requires its own methodology (Grant & Booth, 2009) and cannot be accomplished as a byproduct of preparing the theoretical background for a research question. How, then, can we obtain a more comprehensive view of the research on a topic in which we are interested? This is the primary goal of the literature review. Literature reviews provide a second view: an overview of the field. They structure the field by reflecting on what we already know—theoretically and empirically—and any research gaps that may exist, synthesizing previous research and highlighting potential directions for future research.

The importance of literature reviews is attested by the high impact of journals that specialize in them. Such journals are often among the most cited journals in the social sciences (e.g., according to the Journal Citation Report 2022 from Web of Science, the journal Educational Research Review has been among the top 269 journals in the Social Sciences Citation Index in the category “Education and Educational Research” during the last 10 years).

The need for literature reviews was recognized early on in scientifically “older” disciplines, such as medicine, psychology, and general education. For example, in education, which is among the social science disciplines that are closest to mathematics education and regarded as one of its “mother disciplines”, researchers as early as the 1930s founded journals that published literature reviews exclusively (see, for example, Review of Educational Research). Almost 100 years later, no such journal yet exists for mathematics education. The introduction of the new series of special issues in ZDM - Mathematics Education constitutes a first step toward recognizing literature reviews as an important form of scholarly contribution to mathematics education research.

3 Narrative, scoping, and systematic literature reviews

Within the last century, researchers have intensively discussed the goals of literature reviews and the methods that should be used to achieve these goals. Based on the reviews’ goals, different types of literature review have emerged. Three such types that have been popular in the past and that are of particular importance in the social sciences are narrative, scoping, and systematic reviews.

The author’s perception of the topic lies at the core of a narrative review, for which it is not necessary to describe in detail how the search for the primary studies included in the review was conducted. Because the authors do not systematically search for studies, they may miss some contributions, and their perception of the topic may be distorted. Narrative reviews represent the authors’ subjective view of the topic at hand and rely on the authors’ preexisting knowledge. Therefore, the expertise requirements for the authors of a narrative review are remarkably high.

Scoping and systematic reviews are based on systematic and rigorous search procedures. An important part of the systematic search is the definition of the inclusion and exclusion criteria for primary studies, which must be clearly described in the methodology. Inclusion criteria include databases, journals, or books to be searched and keywords that characterize the topic and are used to identify relevant primary studies. Typical examples of exclusion criteria are methodological criteria (e.g., peer-reviewed studies), language criteria (e.g., only studies in English), and content-related criteria that are highly dependent on the topic of the review. The main characteristics of a scoping review are a broader “scope,” less specific research questions, and less restrictive inclusion criteria (Munn et al., 2018). A systematic review typically requires pre-registration of the review protocol, discussion of the risk of bias assessment, and preparation of the specific summary findings (Munn et al., 2018). Recently, the PRISMA guidelines have provided a useful basis for conducting scoping or systematic reviews (http://www.prisma-statement.org).

To meet the demands of mathematics education research as a rapidly developing academic field, we have decided to establish a series of special issues on literature reviews—that is, we shall regularly publish special issues devoted to reviewing the literature on important topics in mathematics education. The present special issue is the first of this series, for which we have selected key topics and scholars and asked them to prepare a review of approximately 50 interesting and relevant articles published within the last 3–5 years. Each review should be based on and guided by a short theoretical synthesis, and the most important 5–10 papers should be annotated in the reference list. Owing to the general lack of experience in dealing with scientific contributions of this nature, the review process was demanding for authors, reviewers, and editors. We would like to thank the authors and reviewers, who were extremely cooperative and worked diligently to ensure the papers’ quality. We are confident that this work has been worth the effort invested and that it will contribute to the development of mathematics education as a field of research. We hope that you will find the papers in this special issue of interest.