Background and purpose: Studies of education and learning that were described as experiments have been carried out in the USA by educational psychologists since about 1900. In this paper, we discuss the history of randomised trials in education in the USA in terms of five historical periods. In each period, the use of randomised trials was motivated by the research interests and conditions of the era. We have characterised these periods in terms of decades with sharp boundaries as a convenience.
Sources of evidence and main arguments: Although some of the early studies used random allocation (and even random allocation of clusters such as schools), early researchers did not clearly understand the role of randomisation or clearly distinguish it from methods such as alternation. In 1940, E. F. Lindquist published an important book whose goal was to translate R. A. Fisher’s ideas into language congenial to education researchers, but this had little impact on education research outside of psychology. There was a substantial increase in the number of randomised trials during the period from 1960 to 1980, as the US government enacted and evaluated a variety of social programmes. This was followed by a dramatic decrease during the period from 1980 to 2000, amid debates about the relevance of randomised trials in education research. The creation of the US Institute of Education Sciences in 2002 provided major financial and administrative support for randomised trials, which has led to a large number of trials being conducted since that time.
Conclusions: These developments suggest that there is a promising future for randomised trials in the USA. American education scientists must remain committed to explaining why evidence from randomised field trials has an indispensable role to play in making wise decisions about education policy and advancing our capacity to improve education for a productive workforce and a successful society.