The three types of conversion factors all stress that it is not sufficient to know the resources a person owns or can use in order to be able to assess the well-being that he or she has achieved or could achieve; rather, we need to know much more about the person and the circumstances in which he or she is living. Sen uses “capability” not to refer exclusively to a person’s abilities or other internal powers but to refer to an opportunity made feasible, and constrained by, both internal (personal) and external (social and environmental) conversion factors. The real freedom someone has to ride a bicycle is thus dependent on whether these conditions are fulfilled and, in this sense, conversion factors also shape the needs of the individuals in question: in a society in which the capability of riding a bicycle is important (e.g., in order to get to work), it becomes crucial to provide decent roads and an adequate infrastructure (Crocker and Robeyns 2009, 68).