Case-based reasoning for procedure learning by instruction

To control intelligent tools that perform a variety of complex procedures, users need to be able to both modify existing procedure descriptions and communicate new procedures. In one approach, the user describes fragments of a procedure with text, and the tool searches the space of potential procedures for a match. This approach sometimes provides too little guidance for users, yet providing templates for guidance can require an expensive knowledge engineering effort in each new domain. We investigate the use of case-based reasoning to help guide the user, treating previously-defined procedures in the domain as cases. We describe domainindependent methods to find similar procedures while the user creates or modifies a procedure, to suggest potential steps to copy and to manage mapping the variables from the existing procedure into the procedure being edited. In some cases, the mapping tool suggests auxiliary steps to copy along with the desired steps, following an approach similar to derivational analogy. We evaluate the potential of this approach with an implemented tool, CB-Tailor, in a travel domain containing a number of procedures that may be added by the user. Our experiences suggest that the tool can provide useful guidance in a realistic set of situations.