A renaissance of the scientific study of participation has fortunately taken place in recent years. As a consequence of the Convention on the Rights of the Child, forms of participation of children were implemented in different fields of society, especially in the community and at the school level. These programs and attempts are described by science. However, little attention has been paid to the measurement of participation. Therefore, this paper proposes and analyses a measurement instrument for the frequently cited Ladder of Participation by Hart (1992). His model assumes that different levels (degrees) of participation exist, whereby the extent increases with each level (stage).