Representing Control Knowledge as Abstract Tasks and Metarules.- Controlling Expert Systems.- A Quantitative Approach to Approximate Reasoning in Rule-based Expert Systems.- Structural Analysis of Electronic Circuits in a Deductive System.- Building Expert Systems Based on Simulation Models: An Essay in Methodology.- An Approach to Designing an Expert System Through Knowledge Organization.- Garden Path Errors in Diagnostic Reasoning.- Knowledge Organization and Its Role in Temporal and Causal Signal Understanding: The ALVEN and CAA Projects.