"Millions of pounds are spent on educational research each year in the UK alone. By far the greatest proportion of this expenditure is on research which is thought to have practical relevance to educational problems and the vast majority of this is spent on empirical educational research, that is educational research which examines and seeks explanations for actual or proposed educational practices or the kinds of activities, institutions or policies that prepare young people for life (Pring, 2015, p. 27). Invariably, the aim of such research is not merely to gain understanding of these practices, but to improve or replace them with better ones. This practical aspect of educational research exercises most commentators, although it should not be forgotten that educational research can be carried out in a relatively disinterested manner, out of intellectual curiosity (Hammersley, 2006). There are two related issues to be considered here: 1] is it possible to gain knowledge of how educational practices work?; 2] is it possible to use such knowledge to improve existing practices, replace existing ones with better ones or introduce practices which will improve the overall practice of education? In this book, both these questions will be addressed. If the answer to 1] is negative, then it is futile to address 2]. By implication then the answer to 1] will be positive. The answer to 2] will not be negative, but there are degrees of positivity attached to a positive answer and what those degrees are will be crucial to the ultimate claims of the book. It is no exaggeration to say that in recent decades educational research has undergone a crisis of confidence, particularly but not exclusively within the world of educational policymaking. Dissatisfaction has been expressed both with the quality and the usefulness of such research. Conceptual research on education tends to be regarded with some suspicion as something that is either of little practical value or which undermines existing practices. But empirical research fares little better, with scepticism expressed both about its quality (Tooley and Darby, 1998) and about its applicability (Hillage et al., 1998). More recently there have been moves to tie funding to preferred approaches to empirical research such as intervention studies and randomised control trials (RCTs) and to disseminate in accessible form what the findings of such studies are and how they are relevant to the improvement of educational practice. In the UK alone we see organisations such as the Educational Policy Institute (EPI), the Educational Endowment Foundation (EEF), and the Sutton Trust, not to mention meta-researchers Robert Slavin and John Hattie gaining a significant amount of influence in the propagation of studies of 'what works' in educational practice. One should also mention the rising interest in the deliverances of educational research from within the teaching profession, such as ResearchEd in the UK, which betoken a wish by teachers to become more active"--