In the early days of digital design, we were concerned with the logical correctness of circuits. We knew that if we slowed down the clock signal sufficiently, the circuit would function correctly. With improvements in the semiconductor process technology, our expectations on speed have soared. A frequently asked question in the last decade has been how fast can the clock run. This puts significant demands on timing analysis and delay testing. Fueled by the above events, a tremendous growth has occurred in the research on delay testing. Recent work includes fault models, algorithms for test...