This is the second of four essays discussing John Dewey's short essay, 'Education as engineering'. Dewey's views are remarkably timely against the background of recent discussions about the role of evidence in educational practice and a call for research that tells us 'what works'. Dewey's view is nuanced and helps one to see what one should and should not expect from an engineering approach to education. However, Dewey pays little attention to the role of normative judgement in engineering and does not address the question of whether engineering in education might be fundamentally different from engineering in other domains. This paper provides some suggestions for how one may want to articulate this difference and argues that it is important to bear in mind that there are differences between the building of bridges and the 'building' of human beings.