Doing and Seeing Things Differently: A 25-Year Retrospective of Mathematics Education Research on Learning

When we look back over the mathematics education research of the last 25 years as reflected in the pages of this journal and compare the per pectives of the past with those of the present, it is tempting to project onto the activities and intentions of the earlier researchers all of the notions that one finds in today's work. In fact. some current researchers seem quite prepared to argue that certain area of attention in mathematical learning. such as problem solving, constructivism, and individual differences, to name just a few, were with us even then and that nothing has changed very much. One could also say that we have always had teachers. studenrs, and mathematical content as well; but there is ample evidence to suggest that there have been changes over time, changes in the ways that we have researched not only these three general didactical components and the interactions among them but also particular areas such a those others referred to above. Some of these innovations have been quite subtle, others more pronounced. In the main, researchers today are looking at aspects of mathematical learning in ways that were, if not unthought of, at least not common 25 years ago.