BACKGROUND:That the answers elicited through interviews may be influenced by the knowledge of the interviewer is accepted across disciplines. However, in ethnobotany, there is little evidence to quantitatively assess what impact this effect may have. We use the results of a large study of traditional ecological knowledge (TEK) of plant use of the Chácobo and Pacahuara of Beni, Bolivia, to explore the effects of interviewer identity and knowledge upon the elicited plant species and uses.METHODS:The Chácobo are a Panoan speaking tribe of about 1000 members (300+ adults) in Beni, Bolivia. Researchers have collected anthropological and ethnobotanical data from the Chácobo for more than a century. Here, we present a complete ethnobotanical inventory of the entire adult Chácobo population, with interviews and plant collection conducted directly by Chácobo counterparts, with a focus on the effects caused by external interviewers.RESULTS:Within this large study, with a unified training for interviewers, we did find that different interviewers did elicit different knowledge sets, that some interviewers were more likely to elicit knowledge similar to their own, and that participants interviewed multiple times often gave information as different as that from two randomly chosen participants.CONCLUSIONS:Despite this, we did not find this effect to be overwhelming-the amount of knowledge an interviewer reported on the research subject had comparatively little effect on the amount of knowledge that interviewer recorded from others, and even those interviewers who tended to elicit similar answers from participants also elicited a large percentage of novel information.

Although freelisting and semi-structured interviews are widespread methods in ethnobotany, few studies quantitatively examine how these methods may bias results. Using a comprehensive ethnobotanical inventory of palm species, uses and names in the Chácobo tribe of Bolivia, we show that interviews elicit more items than freelists, but the effect is sensitive to sample size, item type and data categorization. This implies that even subtle methodological choices may greatly affect reported results.

The loss of traditional knowledge, concomitant with changes in livelihoods, languages, and demographics of indigenous and local groups, is a global concern. However, documenting such loss poses serious methodological challenges. Comparing the results of contemporary studies with past research is often problematic due to methodological differences. Here, comparing studies that attempted to document the traditional ethnobotanical knowledge of the Chácobo of Bolivia, we tried to examine whether knowledge loss was really occurring across more than 100 years or was only researcher’s perception. The Chácobo are a Panoan-speaking tribe of about 1000 members, first visited by researchers in 1911, and subsequently in the 1950s, 1960s, 1970s, 1980s, and 1990s. Each study had different foci, but all recorded ethnobotanical data. The first more detailed anthropological report exists from the late 1960s, and ecological-ethnobotanical studies were conducted in the 1980s and 1990s. Based on available literature, in particular the botanical studies of Boom (1987) and Bergeron (1998), it seemed that Chácobo plant use now centers on income generation. Both Boom (1987) and Bergeron (1998) perceived that traditional plant use related to household artifacts and medicine, as well as traditional crop varieties had almost disappeared. Here, we hypothesized that plant knowledge documented and the perception of so-called knowledge loss observed in these depended completely on the background of the interviewers and the methods employed, and that in a sufficiently comprehensive ethnobotanical study, we would be able to document all species and uses mentioned in previous studies. We tested this hypothesis by conducting a complete ethnobotanical inventory of almost the entire adult Chácobo population, with interviews and plant collection conducted directly by Chácobo counterparts. The results verify our initial hypothesis and showed that the loss of knowledge perceived in previous studies simply was an artifact of the research methods employed. Traditional crop varieties are still widely grown, most Chácobo know, and can name, traditional artifacts, and many still know the names and uses of medicinal species. However, some knowledge, including the manufacture of artifacts and proficient identification of many medicinal plants, is limited to the older generation.

The Chácobo are a Panoan speaking tribe of about 1000 members (300+ adults) in Beni, Bolivia. Originally nomadic, the Chácabo were relocated to their current main location in the 1960s. Researchers have visited the Chácabo since 1911. A first more detailed anthropological report exists from the late 1960s, and ecological–ethnobotanical studies were conducted in the 1980s and 1990s. The presented work represents a complete ethnobotanical inventory of the entire adult Chácobo population, with interviews and plant collection conducted directly by Chácobo counterparts.