French and English theoretical perspectives in mathematics education research: an overview and discussion of key issues

In this article we focus on issues related to theories in mathematics education as used in both French and English settings. As the final article in this special issue, we review the earlier articles and focus on the key ideas and issues which stand out for us. As with the other articles, we seek to address both common and contrasting perspectives, drawing on the examples which illustrate uses of theory. We end by pointing to issues of validation, scale and policy which challenge both groups and look towards facing such challenges jointly.