There are several different types of conversion factors, and the conversion factors discussed are often categorized into three groups. All conversion factors influence how a person can be or is free to convert the characteristics of the resources into a functioning, yet the sources of these factors may differ. Personal conversion factors are internal to the person, such as metabolism, physical condition, sex, reading skills, or intelligence. If a person is disabled, is in bad physical condition, or has never learned to cycle, then the bike will be of limited help in enabling the functioning of mobility. Social conversion factors are factors from the society in which one lives, such as public policies, social norms, practices that unfairly discriminate, societal hierarchies, or power relations related to, for example, class, gender, race, or caste. Environmental conversion factors emerge from the physical or built environment in which a person lives. Among aspects of one’s geographical location are climate, pollution, the proneness to earthquakes, and the presence or absence of seas and oceans. Among aspects of the built environment are the stability of buildings, roads, and bridges, and the means of transportation and communication. Take the example of the bicycle. How much a bicycle contributes to a person’s mobility depends on that person’s physical condition (a personal conversion factor), the social mores including whether women are socially allowed to ride a bicycle (a social conversion factor), and the available of decent roads or bike paths (an environmental conversion factor).