Children spend several hours daily at school and a range of interactive processes take place in this setting. Systematic study of social interaction in situ is important for developmental psychology and for the scientific understanding of social processes. Assessment strategies need to be designed to identify behavioral mechanisms involved in the regulation of social interactions and social preferences. The methodological contribution of this work is strategically directed to the empirical study of social networks based on a behavioral perspective through the observational design, and our design is diachronic / nomothetic / multidimensional (D/N/M). The uses of polar coordinates analysis allows us to identify the intensity of social connections in a social network. This analysis allows the reduction of data from the value Zsum, introduced by Cochran (1954) and applied by Sackett (1980). Polar coordinates analysis allows the combination of diachronic and synchronic perspectives, through the representation of the values obtained as vector modules and angles (polar coordinates). The nature of the interactive relationship, depending on the quadrant in which it is located is represented by the angle, while the degree of significance depends on the vector module. Data are discussed from the point of view of the flexibility and precision deriving from an adequate observational design and its possibilities for behavioral sociometry.