Teamwork is the collaborative effort of a group to achieve a common goal or to complete a task in the most effective and efficient way. This concept is seen within the greater framework of a team, which is a group of interdependent individuals who work together towards a common goal. The four key characteristics of a team include a shared goal, interdependence, boundedness and stability, the ability to manage their own work and internal process, and operate in a bigger social system. Basic requirements for effective teamwork are an adequate team size. The context is important, and team sizes can vary depending upon the objective. A team must include at least 2 or more members, and most teams range in size from 2 to 100. Sports teams generally have fixed sizes based upon set rules, and work teams may change in size depending upon the phase and complexity of the objective. Teams need to be able to leverage resources to be productive (i.e. playing fields or meeting spaces, scheduled times for planning, guidance from coaches or supervisors, support from the organization, etc.), and clearly defined roles within the team in order for everyone to have a clear purpose. Teamwork is present in any context where a group of people are working together to achieve a common goal. These contexts include an industrial organization (formal work teams), athletics (sports teams), a school (classmates working on a project), and the healthcare system (operating room teams). In each of these settings, the level of teamwork and interdependence can vary from low (e.g. golf, track and field), to intermediate (e.g. baseball, football), to high (e.g. basketball, soccer), depending on the amount of communication, interaction, and collaboration present between team members. E. g. Team work coordinates the work as early as possible History The Oxford English Dictionary records the use of "team-work" in the context of a team of draught animals as early as 1800. Even though collaborative work among groups of individuals is very prominent today, that was not the case over half a century ago. The shift from the typical assembly line to organizational models that contained increasing amounts of teamwork first came about during World War I and World War II, in an effort for countries to unite their people. The movement towards teamwork was mostly due to the Hawthorne studies, a set of studies conducted in the 1920s and 1930s that