I have worked in education, social care, outdoor education and youth work as a front line worker, manager and at times, leader. I have encountered the challenge of measurement of progress in all of these settings. The emphasis on impact evidence varied across contexts, but one constant was the need to develop a form of evaluation that; benefitted the young people I worked with, allowed me to stay true to my values as a practitioner, and met the needs of the organisation that I was employed by. I taught  research methods on a Masters programme in Leading Integrated Children’s Services at the University of Cumbria, I was the Head of Research at Brathay Trust, a youth work organisation, and am now a director at Indigo Children’s Services supporting children’s centres, schools and children’s services to provide outstanding services for children and families. Evidencing the efficacy of services and impact for young people remains a constant challenge in all of these roles and is the impetus for this book.   I’ve worked both nationally and internationally as a practitioner, educator, evaluator and researcher in the area of youth development. My interests in the area are rooted firmly in practice, the foundations of which were laid whilst working in the USA as an experiential educator. My interest in understanding practice more and more led me to study at undergraduate, masters and doctoral levels. In 2011 I completed my PhD in empowerment and critical pedagogy, working with young people and practitioners to understand the process of empowerment in youth development. Now, as the Head of Research at Brathay Trust, I work alongside practitioners and students to understand, evaluate and develop our practice.  I originally came to the University of Cumbria with a background in mainstream psychology. However, I have always been interested in young people, the challenges they face and in thinking about how psychology can be used in practical, useful ways to help practitioner understand and support young people. My MSc in Applied Psychology and PhD in Community Psychology allowed me to focus on these interests. For many years I worked with Youth Workers both in training and in the field. I also worked with directly with young people on a range of projects, including diversion projects and youth homelessness.  I currently teach psychology and research methods to wide range of students (including youth work, criminology, policing and social science students) at the University of Cumbria.