Mixed-Grade Elementary-School Classes and Student Achievement

The entrenched and widespread lockstep system of schooling, where students are locked into a year or grade based on age and "step" forward with their age peers, means there is a general perception that single-grade classes are the norm. Yet mixed-grade classes of one sort or another have always been common and typically still account for one quarter to one third of all classes in developed countries and more in developing countries. Such classes are mostly formed by necessity, because of insufficient students (as in remote rural areas), insufficient teachers, or uneven grade enrolments. Some mixed-grade classes, however, are formed by choice. The issue of terminology is particularly pertinent when trying to separate findings for the different types of mixed-grade classes in elementary schools: nongraded, multiage, multigrade, composite, and stage classes. Each has different contextual characteristics that could potentially influence student achievement. Yet characteristics of these classes have traditionally not been well described in research publications; therefore, it is not always possible to clarify which type of class is being studied. Although secondary schools also sometimes have mixed-age, mixed-grade classes (e.g., vertical semester organisation), they are not discussed here.