Why do students choose to study particular courses and what is the impact of these choices on their later progression? Quite often the reason for the choice appears to be obvious and straightforward, and their after course trajectory is already determined. The education system has, what some may view as an easy to follow progression route when students reach the end of Key Stage 4, i.e. GCSE to A level, and then university for those who meet the criteria. With A levels considered by many to be the 'gold standard', there is probably no expectation by schools, parents and students that they will do anything else. But what about those who may not meet the criteria and A levels may not be the most appropriate progression route for them? This thesis examines the factors that influence the choices made by students who have decided to study a course other than A level. This is done through longitudinal case studies derived from the use of questionnaires, focus groups and individual interviews using BTEC L3 Science as a vehicle. Four educational establishments agreed to participate in the research to varying degrees, with one establishment providing the participants who provided the case studies.Many previous studies that have investigated student choice have often done so from either the perspective of structural factors or individual agency, but not usually both. Hemsley-Brown and Fosketts' 2001 Integrated Model of Educational Choice has been used to provide a theoretical framework as it allows consideration of both structural factors and individual agency. The model was used at two different points in the research, but in a different way at each point. The result was a series of individual stories that gave an insight into the factors that influence student choice and also how the balance of power in the decision making process shifted in favour of the student as they progressed through the course. At the start of the course structural factors such as the systems that exist within education had a significant role in the choice of course for the students, to the point where it was effectively a 'non-choice' for them. By the end of the course individual agency played a significant role and the students were able to adapt and make the systems work for them to enable them to make the best possible choices to meet their own needs.