A 2003 state-of-the-art report on seismic analysis for structural engineers would be similar to one that could have been produced in 1993 or 1983, and in fact not much different from 1973. Development of structural engineering analysis tools has not kept pace with the rapid improvement in computer hardware. Our common analysis tools ignore either nonlinearity (response spectrum analysis), dynamic effects (pushover analysis), or both (equivalent static analysis) even though these effects are critical in evaluating the pe1formance of a structure under earthquake loads. This paper examines the effects of nonlinearity and dynamic loads on the response of structures and illustrates cases where ignoring either of these leads to erroneous results. Given this need for nonlinear dynamic analysis, impediments to more widespread use are discussed and areas where more research information is required are identified. The conclusion of this paper is that our profession needs to be more active in implementing software development, graduate training in analysis and the processing of research results to a format suited for analysis models. We have a wealth of research information providing detailed response of structural components but, by failing to convert this into detailed rules for nonlinear analysis, we are neglecting much of the value in this research.