%A Timo A. Nieminen %A Serene Hyun-Jin Choi %A Mark Bahr %A Nan Bahr %T Improving behaviour classification consistency: a technique from biological taxonomy %X Quantitative behaviour analysis requires the classification of behaviour to produce the basic data. In practice, much of this work will be performed by multiple observers, and maximising inter-observer consistency is of particular importance. Another discipline where consistency in classification is vital is biological taxonomy. A classification tool of great utility, the binary key, is designed to simplify the classification decision process and ensure consistent identification of proper categories. We show how this same decision-making tool - the binary key - can be used to promote consistency in the classification of behaviour. The construction of a binary key also ensures that the categories in which behaviour is classified are complete and non-overlapping. We discuss the general principles of design of binary keys, and illustrate their construction and use with a practical example from education research. %D 2002 %K classification; behaviour analysis; binary keys %P CHO02101 %L cogprints3963