Unrealistic parameter values and poor experimental agreement are two problems often encountered using the MOS3 model in SPICE2. The source of the discrepancy is attributed to MOS3's simplified treatment of the mobility degradation phenomenon, which generally results in an artifically exaggerated value for the carrier velocity. Practically, this discrepancy can be eliminated by introducing a new empirical factor (DEL) into the mobility model, thereby permitting SPICE users to accurately simulate both triode and saturation regions of p- and n-channel transistors. DEL is determined using an extraction algorithm which systematically extracts MOS3 parameters and characterizes the extent of mobility degradation in the transistor's triode region.