Developmental mentoring is one of two dominant approaches to mentoring; the other being sponsorship mentoring. (Sometimes described as relational v instrumental mentoring). As one of the pioneers of developmental mentoring, David Clutterbuck set out to explore what occurred with this kind of learning relationship, using a longitudinal research design that involved three stages of questionnaires to both mentors and mentees, in their dyads, within formal mentoring programmes and over a 12 month period. Because all the existing measurement instruments were based on sponsorship mentoring, it was necessary to design and validate new measures for most of the constructs. The data analysis demonstrated that sponsorship mentoring and developmental mentoring were indeed separate constructs and identified relationships between goal alignment, behaviours by mentor and mentee, perceived quality of relationship and outcomes for both mentor and mentee. The validated questionnaires and database have subsequently been used in other research into developmental mentoring.