Within sociology, sociometry has two main branches&colon; research sociometry, and applied sociometry. Peer rejection has been measured using sociometry and other rating methods. Sociograms are the charts or tools used to find the sociometry of a social space. Using the method of sociometry he visualized these connections in several sociograms. Northway was a pioneering researcher in the field of sociometry, examining children's social groups. Moreno's term sociometry is often used in relation to psychodrama. He made studies of sociometry at Sing Sing Prison in 1931. Zerka was herself an expert in psychodrama and sociometry, and continued her late husband's work. His clinical specialization is in psychodrama and sociometry, with an academic specialization in intellectual disabilities. All these approaches share much of their basic principles with Sociometry. Sociometry is a quantitative method for measuring social relationships. The term sociometry relates to its Latin etymology, "socius" meaning companion, and "metrum" meaning measure. Moreno developed sociometry as one of the newly developing social sciences. Sociometry measures the connections between individuals in any group, from small groups to world issues.