Modeling

In the text Sporre calls this technique manipulation but it can also be called modeling which is the process of manipulating soft materials to create a three-dimensional form (72).  Unlike carving, modeling requires soft substances that can be easily and rapidly shaped by the sculptor's hands. The soft materials that can be used are clay, wax, or plaster. The picture below shows a man modeling a face sculpture. 

http://www.tsos.org/news/2006/0601_lucchesi.jpg