Every group, however small or informal, possesses an inner structure of attraction, indifference, and repulsion that does not always coincide with its formal or official organisation. A classroom has a seating chart drawn up by the teacher, but it also has an invisible chart of friendships, rivalries, and cliques drawn up by the students themselves. The sociometric method is the technique devised to bring this informal, affective structure into the open and to represent it in a form that can be described, measured, and compared. It occupies a distinctive place among the tools of social research because it does not merely ask what people think or believe in the abstract; it asks whom they choose, whom they avoid, and why, thereby mapping the actual pattern of interpersonal relations within a defined group.