 Cooperative Education Programs (often referred to as 'co-ops') are similar to internships insofar as they are employment opportunities offered to undergraduate students by engineering employers, however they are intended to take place concurrently with the students' academic studies.Co-ops are sometimes part-time roles that are ongoing throughout the academic semester, with the student expected to invest between 10–30 hours a week depending on the severity of their course load.Some American universities, such as Northeastern University and Drexel University, incorporate co-ops into their students' plan of study in the form of alternating semesters of full-time work and full-time classes; these programs typically take an additional year to complete compared to most 4-year undergraduate engineering programs in the US, though Northeastern currently has a 4-year undergraduate program that integrates full-time co-ops with full-time studies.