The highest academic rank is based on peer review of the scholar's work, and a process of election by his peers as specified by the rules of each college or university. Once elected to the rank of (associate) professor, the colleague has achieved tenure and cannot be fired or laid off from their position, except for criminal action.
Most colleges and universities require professors to have a PhD, MD or JD degree. People with lower level degrees such as a Masters degree usually can only take teaching positions. In fields such as business, public policy, foreign languages (linguistics), and literature it is fairly common for professorships to be awarded to people without advanced degrees but who have had substantial real-world experience. Occasionally, universities will give a prominent person an honorary professorship even if that person does not have an advanced degree. Such positions are symbolic and do not carry the teaching or research responsibilities demanded of other professors.
Types of Professors
- Professor (general) - A college or university teacher who ranks above an Associate Professor. Sometimes colloquially referred to as a "full Professor."
- Associate Professor - A college or university professor who ranks above an Assistant Professor and below a Professor. Assistant Professors typically gain the rank of Associate upon earning tenure.
- Assistant Professor - A college or university teacher who ranks above an instructor and below an associate professor. This is a typical entry-level position; Assistant Professor usually do not have tenure.
- Adjunct Professor - Attached to a faculty or staff in a temporary or auxiliary capacity.
- Visiting Professor - A professor on leave who is invited to serve as a member of the faculty of another college or university for a limited period of time, often an academic year.
- Professor Emeritus - Retired but retaining an honorary title corresponding to that held immediately before retirement.
- The American Heritage® Dictionary of the English Language: Fourth Edition. 2000.