James Kippen & Bernard Bel
Anthropological Quarterly (1989), 62, 3: 131-144
Abstract
A major problem in ethnographic description may be summed up as the search for ways to disentangle folk from analytical models. Knowledge-based systems have contributed to the development of formal structures for the manipulation of symbols associated with particular physical and conceptual phenomena. Importantly, their output can be interpreted by experts in the domain. This provides evaluation procedures for models elaborated jointly by analysts and informants. This paper describes an interactive system in which knowledge is represented as production rules in a format derived from the theory of formal languages. Modus ponens and modus tollens are explained and compared to derivation schemata in first-order predicate logic. The results of an application to the study of North Indian tabla drumming are assessed. We conclude that (1) knowledge represented at a low theoretical level fails to descriminate between the input from informants and the intuitive assumptions of analysts, (2) experimental procedures can be improved considerably if the system is designed to perform automated knowledge acquisition (using probabilistic grammars and inductive learning).
Excerpts of an AI review of this paper (Academia, June 2025)
Summary of the Work

The article focuses on the use of computational approaches — particularly knowledge-based systems — to address the challenge of producing consistent and systematic ethnographic descriptions. The authors draw on their research with the Bol Processor (BP), a formal language-based system originally developed to represent and generate sequences of verbal drum syllables (bols) in North Indian tabla performance. They describe how the BP’s grammar formalism, inference engine, and membership tests facilitate iterative interaction between an analyst and informants (expert musicians). By demonstrating the system’s ability to produce, recognize, and evaluate permissible melodic or rhythmic variations, the authors aim to illuminate how computers can be more deeply integrated into anthropological and ethnomusicological research.
Key Contributions
Formal Grammar and Pattern Representation: The paper offers a clear explanation of how context-free and context-sensitive grammars can be used to specify culturally valid musical structures. In particular, the authors highlight the importance of representing patterns and constraints on musical improvisation in a generative format.
Interactive Methodology: A central point is the iterative feedback loop that allows informants to assess computer-generated sequences and provide corrections. This “apprentice-like” interaction underscores how computational tools can help researchers refine theoretical models of cultural knowledge in near-real-time.
Probabilistic Grammars: The authors incorporate a weighting system for production rules, thereby accounting for the relative likelihood of different musical derivations. This approach not only adds realism to the generative process but also tackles common issues with purely enumerative or random output.
Membership Testing: The membership test, which decides whether a newly proposed sequence belongs to a given grammar, is described as an efficient, deterministic bottom-up parser. This feature is significant because it allows informants to offer novel variations while enabling the system to quickly judge their adherence to the emergent rule set.
Reflections on Folk vs. Analytical Models: The article raises important anthropological questions about the boundary between informants’ internalized (folk) knowledge and the analyst’s formal (re)construction. The authors’ frank discussion of the challenges involved, such as the risk of overformalizing or “anticipating” informant knowledge, is methodologically relevant.
Strengths
- The paper emphasizes the value of combining fieldwork with computational experimentation. This dual approach—grounded in real ethnographic and musical practice—provides a compelling demonstration of how artificial intelligence techniques can advance the study of music and culture.
- Clear examples illustrate code structures, parsing mechanics, and the grammar design. These concrete details will help other researchers adapt or replicate the Bol Processor approach in different cultural or musical contexts.
- The account of iterative knowledge acquisition highlights a collaborative research dynamic, showing how insight flows back and forth between informants and computational models, rather than being a unidirectional exercise of extracting information.
Conclusion
This study offers a thoughtful and innovative approach to bridging ethnographic inquiry with computational models. By showing how arrangements of symbolic musical data can be systematically generated, tested, and refined in conjunction with human experts, the authors illustrate a novel and promising method for ethnographic description. The paper encourages a nuanced understanding of both the potential and limitations of using expert systems to capture the complexity of cultural knowledge.