In this chapter, particular importance is given to the selection of the intern as it is seen as a potential job placement in the company but also as a possible element of imbalance in the company. The need is to work side by side with the internal tutor for the choice of the student that best fits the company reality. It is also advisable to take into account more practical aspects ranging from the interest of the young person to the contents of the project and the type of company (very useful, in this sense, may be the letter of motivation attached to the curriculum) and to organizational and logistical aspects (such as, for example, the proximity between home and company). The third paragraph also gives indications on how to evaluate an intern, but it must be emphasized, however, that a good relationship with the sending school is mandatory. Many of these indications are more valid when starting as a company the activity of hosting a student in training-work a new relationship with a school is started. And here the process of pairing between student-company that realizes a co-planning of the scholastic-working path between school, company and student is of great importance. Thus, from a phase of close collaboration between the student and the internal tutor (that of the school) we move on to a phase in which the collaboration between student and company tutor. Important elements in this panorama are an Institute / company Convention in which the methods for implementing the alternation school-work project and a training pact between student and company are defined. The importance of a careful choice of the company tutor is underlined.