This thesis investigates the parameters of achieving electromagnetically induced transparency, or EIT. The technique of EIT manipulates the properties of atoms to partially cancel the usual absorption of laser light. In this experiment, the effect was observed using the D1 line of rubidium vapor and a Λ -configuration between the degenerate magnetic sublevels of the 5S1/2(F=1) and 5P1/2(F=1) hyperfine states. Among the parameters investigated were the linear and circular polarization of the light used to drive the transitions, the size of the laser beam used, the effects of the temperature of the rubidium interaction cell on EIT, the density of the rubidium atoms in the interaction cell, and the effects of changing the power of the fields used to drive the transitions. Careful measurements of these parameters were made