INTRODUCTION
An increasing number of studies in recent years have been devoted to interpreting data contained in the various ecclesiastical registers kept by early Franciscan missionaries in California. These mission registers contain valuable information regarding California Indian history, settlement geography, demography, family structure, marriage patterns, and relations with the Spanish colonial system. These data are important because they supplement and test statements about California Indian lifeways occurring in other historical documents and in the records gathered by early ethnographers. A great advantage to the ethno-historic information contained in the mission registers is that it covers a sizeable sample of the native population, thereby allowing analysis on a regional scale.
Although an excellent opportunity is provided to obtain significant anthropological information, the use of mission register data is not entirely straightforward. The registers may contain any number of clerical errors, difficult handwriting, faded ink, missing pages, inconsistent renderings of Indian names, and cross-cultural misinterpretations. Because of the increasing use of mission registers for reconstructing California Indian culture, it is appropriate to review some common sources of error so that other researchers may be aware of potential problems which are involved in using this type of material. Examples are drawn from the author’s mission register studies of the Chumash Indians primarily using data from Missions Santa Barbara, La Purisima, and Santa Inés.