or facilitated by a lecturer or tutor; professor is the job-title of a senior academic (in AmE, at some universities, the equivalent of the BrE lecturer is instructor, especially when the teacher has a lesser degree or no university degree, though the usage may become confusing according to whether the subject being taught is considered technical or not; it is also different from adjunct instructor/professor). In AmE each class is generally taught by a professor (although some US tertiary educational institutions follow the BrE usage), while the position of lecturer is occasionally given to individuals hired on a temporary basis to teach one or more classes and who may or may not have a doctoral degree. The word course in American use typically refers to the study of a restricted topic or individual subject (for example, "a course in Early Medieval England", "a course in integral calculus") over a limited period of time (such as a semester or term) and is equivalent to a module or sometimes unit at a British university. In the UK, a course of study or simply course is likely to refer to the entire programme of study, which may extend over several years and be made up of any number of modules, hence it is also practically synonymous to a degree programme. A few university-specific exceptions exist: for example, at Cambridge the word paper is used to refer to a module, while the whole course of study is called tripos. A dissertation in AmE refers to the final written product of a doctoral student to fulfil the requirement of that program. In BrE, the same word refers to the final written product of a student in an undergraduate or taught master's programme. A dissertation in the AmE sense would be a thesis in BrE, though dissertation is also used. Another source of confusion is the different usage of the word college. (See a full international discussion of the various meanings at college.) In the US, it refers to a post-high school institution that grants either associate's or bachelor's degrees, and in the UK, it refers to any post-secondary institution that is not a university (including sixth form college after the name in secondary education for years 12 and 13, the sixth form) where intermediary courses such as A levels or NVQs can be taken and GCSE courses can be retaken. College may sometimes be used