In an attempt to overcome some of the drawbacks of existing taxonomic keys, we have experimented with a computerized version of a key, changing the interface to the key, but leaving the information contained in the key essentially unchanged. This is in contrast to most previous work on the use of computers in taxonomy, where work has concentrated on alternative identification techniques and techniques for manipulating taxonomic data. Hopkin's (1991) Key to the Woodlice of Britain and Ireland was converted (including the diagrams and colour photographs), into a hypertext document using the Unix Guide hypertext system. An experiment was conducted where test subjects with a wide range of experience of taxonomic keys and computing skills were asked to identify woodlouse specimens using the paper and hypertext forms of the keys. The results showed that test subjects were more likely to obtain an identification with the hypertext version of the key, they found it easier to use and preferred using it to the paper version of the key. However, there were indications that test subjects were more likely to obtain a misidentification using the hypertext key than the paper version of the key. Further work is needed to discover the possible causes of the increased frequency of misidentifications, and ways in which the usability of hypertext keys can be further enhanced.