This work correlates the linear to the nonlinearseismic responses. Different nonlinear effects wereevaluated, and predictions of the seismic demandswere made with acceptable reliability for twoperformance levels. The first of which was theUBC'97, which represents seismic events that have a10% probability of exceedance in 50 years (10/50).The other level was the Near-Field strong groundmotion (N-F).A set of three correction bias factors were thenevaluated, which correct for individual nonlineareffects. Four response parameters were investigatedwhich are the story displacements, drift angles,ductility demands, and shears. It was found that theresponse parameters are generally overestimated inthe linear elastic analysis, compared to thebilinear models. The stiffness degradation andstrength deterioration reduce the difference betweenthe linear and nonlinear responses. The P-Deltaeffects, however, were found to have negligibleparticipation to the response of the building underboth groups of earthquakes. It is believed that thechoice of structural system is causing this behavior.