A performance, in performing arts, generally comprises an event in which a performer or group of performers behave in a particular way for another group of people, the audience. Choral music and ballet are examples. Usually the performers participate in rehearsals beforehand. Afterwards audience members often applaud. After a performance, performance measurement sometimes occurs. Performance measurement is the process of collecting, analyzing and/or reporting information regarding the performance of an individual, group, organization, system or component. The means of expressing appreciation can vary by culture. Chinese performers will clap with the audience at the end of a performance; the return applause signals “thank you” to the audience. In Japan, folk performing arts performances commonly attract individuals who take photographs, sometimes getting up to the stage and within inches of performer’s faces. Sometimes the dividing line between performer and the audience may become blurred, as in the example of “participatory theatre” where audience members get involved in the production. Theatrical performances can take place daily or at some other regular interval. Performances can take place at designated performance spaces (such as a theatre or concert hall), or in a non-conventional space, such as a subway station, on the street, or in somebody’s home.