Two approaches to the analysis of level crossing are presented. A theoretical approach utilizes values of the hyperfine coupling constants to predict the entire level structure of a system, including all level-crossing data of interest. A second approach suggests a procedure for determining hyperfine parameters with reasonable accuracy, based on three or four measured quantities. Results of this procedure in 2 2P lithium give the contact, dipole, and orbital hyperfine coupling constants as -9.806 +/- 0.117, -1.909 +/- 0.034, and 8.638 +/- 0.39 MHz, respectively. This work reemphasizes the fact that an accurate determination of magnetic hfs requires three parameters to fully define the three independent magnetic hyperfine interactions.