Laban movement analysis is contemporarily categorised in various way. Originally, these categories were very basic and Laban himself referred mostly to Eukinetics - which is his effort studies - and Choreutics - which is Spatial Harmony theory. His student Irmgard Bartenieff later further elaborated these categories in four - Body, Effort, Shape and Space - and this system, known as BESS is commonly taught today. However, BESS is not the only organisation of Laban's theory in use. In the U.K. for example, more influenced by Lisa Ullmann, another student of Laban, the categories are Body, Effort, Space and Relationship with Shape being interwoven into Body, Space and Relationship.