The Cope rearrangement is a highly stereospecific, concerted reaction of considerable synthetic utility. Experimental product distributions from the reaction of disubstituted 1,5-hexadienes can be readily understood by computer modeling of the various possible transitions states. Semi-empirical methods give relative energies of transition states that parallel those of more sophisticated methods at a fraction of the computational time. Visual analysis of computed transition-state geometries allow students to interpret the computational results by analogy to the familiar chair and boat conformations of substituted cyclohexanes. (Contains 2 figures and 2 tables.)