In this work, they are considered like general properties of a group, the following characteristics: The interaction, the cohesion, structures, the norms and the goals of the group. Next each of them is defined: The Interaction: This referred to the reciprocity between two or more people (reciprocal effect), includes means and procedures through which the individuals interact to each other (they are related), to carry out the tasks of development, maintenance and growth of the group. This is a common property or characteristic of the small groups (15 maximum participants), and the one that is developed more in praxis. The Cohesion: It is the degree in which a group is attractive for its members, it comes given by " " FEELING DE PERTENENCIA" " to the group. Also it is defined to him, like a set of forces that act on the members of the group, to do them to remain in him. The cohesion reinforces the bows of camaraderie and friendship, between the members of the group. The investigations realised around the cohesion, demonstrate that the same requires that the members of a group own a very high moral, feelings of property and of identification with its companions; this characteristic instills underlyingly, between the participants of a group. The Structure: One talks about organization and a the norms of behavior of the group.
This property, implies a hierarchic system, in which the group grants to its different members, positions and papers according to: capacities, abilities, knowledge, status, age, etc. The Norms: They constitute the frame of reference for the behavior of the group. Also it is defined, like the rules of conduct propose and accepted by all the members, for the good operation, maintenance, growth and development of the group. Metas: They constitute the result waited for by the group; in order to obtain the same, the members of the group work jointly.