The present invention provides, in one aspect, a method of testing an electrical breakdown characteristic of a dielectric in a microelectronic device. This method includes determining a first dielectric breakdown voltage distribution of a first test sample by using a first voltage ramp rate, determining a second dielectric breakdown voltage distribution of a second test sample by using a second voltage ramp rate and determining a spacing distribution between conductive lines in the first and second test samples based on a field acceleration factor associated with the dielectrics of the first and second test samples, the first and second voltage ramp rates, and a difference between the first and second breakdown voltage distributions. This spacing distribution is used to determine corrected electric breakdown fields based on a measured breakdown voltage of a test sample, to improve microelectronic-device screening for interconnect dielectric reliability.