Income is only one feature of occupational prestige. The length of education required for the job, the abstract thought it entails, and the autonomy of the position are other features. An electrician can be certified after completing on-the-job training or taking a technical school course for a few months. Electrical wiring is a step-by-step process done "by the numbers." It does not require creativity. Finally, an electrician works for someone else either for wages or for clients who expect them to follow reasonably strict schedules of accountability. Professors require years of formal education and life experience. They are able to analyze situations, especially in social sciences such as sociology, and present multiple approaches to problem solving. Although there are expectations made of professors by the chair, dean, and others in the chain of academic command, there is a great deal of independence afforded the professor on how he or she accomplishes the goals presented. An electrician's higher income is due to high hourly wages and longer hours of work.