The new percolation threshold model developed by this author, the modified Landauer model identified by this author and the original Landauer model were all found to be full concentration range models that describe S-shaped curves normally found in electrical conduction measurements of composites. It was also found that each of  these models had three important conditions that occur at the same concentration; the concentration at the inflection point, φ_ip, the concentration of maximum slope and the concentration at maximum slope that can be extrapolated back to get the maximum percolation threshold, φ_ciMax. These three conditions were found to be extremely important when trying to describe the percolation threshold process as a function of concentration for electrical conduction measurements of composites. In general, the new percolation threshold model developed by this author and the modified Landauer model identified by this author both gave good fits of Clingerman’s electrical conduction data for three different carbon fillers in nylon 6,6. However, the orginal Landauer model was found to yield a vastly inferior fit of the same data. One significant difference between these models was that the new percolation threshold model developed by this author was found to have a well defined maximum whereas the modified Landauer model identified by this author and the original Landauer model did not have well defined maximums where the first derivative was equal to zero.