A teacher in general understands the ages and cognitive abilities of his/her students. The teacher also usually knows the student's personality, speech vernacular, and style of writing from previous work and interaction with the student. Therefore, one major way that a teacher can detect plagiarism is when there are obvious changes in use of vocabulary or style of writing from the student's
. previous and regular work. Teachers also are usually in control of the topics given in the assignments and therefore are relatively familiar with the resources that most of the students would use as references to help them with their writing. Also, a teacher who has been teaching the same subject for many years has probably seen and read a lot of papers on the same material year after year. Having had experience with students over many years makes it easy for a teacher to know the subject, resource material, and the good and bad of what the student's can produce.
