The SOPHIE program, which implements mixed initiative computer-assisted instruction within a simulated electronics trouble shooting training laboratory interaction, has been extended in several ways. The language processor now accepts ellipses and other nonspecific requests and resolves these from dialog context. A help requesting facility has been provided which will suggest possible faults (based on the student's knowledge about the circuit at the time of request) which could explain the symptoms he has observed. The net effect of modifications is that a dialog is much more like a conversation with a very skilled tutor who can infer what a students means, based on a complete interaction session, and respond appropriately. The resulting program can be accessed through the ARPA network of computers. (SK)