P r a c t i c a l a n d E t h i c a l C o m p l i c a t i o n s o f P a r t i c ip a t o r y R e s e a r c h E thnographers conducting research ordinarily have multiple goals. While gathering in-depth information about topics of interest, they are also often planning to improve their scholarly reputations and advance their careers by writing articles and books about their findings. Achieving these goals is impossible without the help of the people anthropologists variously call informants, interlocutors, and collaborators. 1 Because ethnographers recognize their debts to their collaborators, they usually thank them in the acknowledgments accompanying their publications. Anthropological codes of ethics almost always begin with the injunction to cause no harm to the people they work with. Ethnographers differ, however, in the extent to which they think they have additional obligations. Some anthropologists conduct a year of purely academic research, write up their results, and seldom or never return to their field site. Even though they ordinarily have done no harm to the people they worked with, the exchanges of these anthropologists with their collaborators might reasonably be regarded as unequal or even exploitative. Many anthropologists, including the contributors to this issue, therefore urge ethnographers to work with their interlocutors on projects aimed at improving the lives of people in their research sites. Some ethnographers regard such collaboration as an ethical obligation; others less prescriptively regard it as a good thing to do in certain circumstances. Certain features of Mesoamerica affect collaborative research in the region. As Little and Rees note in their introduction, Mesoamerica has an extraordinary amount of cultural and historical diversity in a small space. This diversity and the region's contiguity to the U.S. have attracted many ethnographers to the area but the number of anthropologists conducting research in the region is not the only reason why opportunities for participatory ethnography has been so common in Mesoamerica. Development programs run by national and regional governments, international aid organizations, and NGOs are found throughout the region. Since the Mexican revolution in the early 20th century, state organizations in that country have promoted archaeology, crafts, dance, and food. Anthropology has been taught in Mexican universities for many years. As a group, Mexicans are