From its beginnings in Cincinnati in 1906, cooperative education has evolved into a program offered at the secondary and post-secondary levels in two predominant models (Grubb & Villeneuve 1995). In one model, students alternate a semester of academic coursework with an equal amount of time working, repeating this cycle several times until graduation. The parallel method splits the day between school and work, typically structured to accommodate the student's class schedule. Thus, like school-to-work (STW), the co-op model includes school-based and work-based learning and, in the best programs, "connecting activities" such as seminars and teacher-coordinator work site visits. These activities help students explicitly connect work and learning.
Other models, such as the sandwich model and the American-style semester model instead have students work a 40-hour work week for a set amount of time, typically between 12 weeks and six months. After this period is over, students return to the classroom for an academic semester after which they may have another work term. This cycle often repeats multiple times, adding a year or more to the students' university career. In this model, students' do not receive a summer break from school but instead are either working or in school for 12 months of the year. Before or during this work experience students may complete activities designed to maximize their learning on the job, such as online workplace conduct courses or reflective activities.
Co-op's proponents identify benefits for students (including motivation, career clarity, enhanced employability, vocational maturity) and employers (labor force flexibility, recruitment/retention of trained workers, input into curricula) as well as educational institutions and society (ibid.). Beyond informal and anecdotal evidence, however, a familiar refrain in the literature is the lack of well-done research that empirically demonstrates these benefits (Barton 1996; Wilson, Stull & Vinsonhaler 1996). Barton (1996) identifies some of the research problems for secondary co-op as follows: federal data collection on high school co-op enrollments and completions ceased in the 1980s; some studies use data in which co-op was not isolated from other work experience programs. Ricks et al. (1993) describe other problems: due to lack of a clear or consistent definition of cooperative education, researchers cannot accurately identify variables and findings cannot be compared; theory is not well developed; theory, research, and practice are not integrated; and co-op research does not adhere to established standards.
Another set of problems involves perceptions of the field and its marginalization. Because of its "vocational" association, co-op is not regarded as academically legitimate; rather, it is viewed as taking time away from the classroom (Crow 1997). Experiential activities are necessarily rewarded in post-secondary promotion and tenure systems (except in certain extenuating situations), and co-op faculty may be isolated from other faculty (Crow 1997; Schaafsma 1996). Despite the current emphasis on contextual learning, work is not recognized as a vehicle for learning (Ricks et al. 1993). Schaafsma (1996) and Van Gyn (1996) agree that the field places too much emphasis on placements rather than learning. Wilson, Stull & Vinsonhaler (1996) also decry the focus on administration, logistics, placements, and procedures.
Some institutions are fully dedicated to the co-op ideal (such as Northeastern University, Drexel University, Georgia Institute of Technology, RIT, Kettering University, LaGuardia Community College, and Purdue University). In others, the co-op program may be viewed as an add-on and therefore is vulnerable to cost cutting (Wilson, Stull & Vinsonhaler 1996). Even where co-op programs are strong they can be threatened, as at Cincinnati Technical College when it became a comprehensive community college (Grubb & Villeneuve 1995) or LaGuardia during a budget crisis (Grubb & Badway 1998). For students, costs and time to degree completion may be deterrents to co-op participation (Grubb & Villeneuve 1995). Other deterrents may include financial barriers, aversion to moving frequently due to family obligations or other pressures as well as difficulty managing the job search during a school semester.