 Boscana's first ethnographic contribution resulted from an 1812 questionnaire sent by the Spanish government to the missionaries of Alta California (Geiger).The task of preparing a response on behalf of Mission San Juan Capistrano of the "Juaneño" may have stimulated the missionary's latent interest in the native culture.While at San Juan Capistrano, Boscana composed two versions of a detailed ethnographic sketch of the Acagchemem ("Juaneño") Native Americans, who were primarily speakers of a dialect of the Luiseño language but probably also included Tongva language ("Gabrieliño") speakers from the north.