Two systems were evaluated for drawing Lewis structures of period 2 and 3 non-metallic compounds: the octet rule and minimization of formal charge. The test set of molecules consisted of the oxides, halides, oxohalides, oxoanions, and oxoacids of B, N, O, F, Al, P, S, and Cl. Bond orders were quantified using experimental data, including bond length, bond enthalpy, and the force constant of the IR symmetrical stretch. The results show for compounds containing period 3 central atoms or boron, Lewis structures that minimize formal charge give bond orders that are better correlated to the experimental observations. However, compounds with nitrogen and oxygen central atoms are better characterized by Lewis structures following the octet rule. These results are summarized as follows: for nonmetal central atoms, Lewis structures that minimize formal charge give the best prediction of bond order, with the restriction that period 2 central atoms are limited to a formal maximum of eight valence electrons. Chemical educators are urged to take these results into account when presenting Lewis structures to their students. (Contains 5 tables and 6 notes.)