This book has been developed for interested practitioners in the field of education and training, who use or wish to use group methods. Despite the author's 25 years of experience in analyzing the broad areas of activities that fall under the group's work, he is also interested in clarifying the complex effects that these methods can have on those working in this field. He confirms with evidence and argument that the practitioner can reap the maximum benefits and gains when he adheres to the basic methods of ideas selected with care and care. For this reason, this book was divided into two parts: the first section deals with the theoretical aspect, while the second section emphasizes practical practice