In this talk we study several issues that arise in the comparison of the Standard Model Effective Field Theory to experimental data. These issues include the appearance of degeneracies between Wilson coefficients that occur when analyzing LHC data in the SMEFT framework, and the impact of higher-order terms in the SMEFT expansion on theoretical predictions. We identify several expected high-precision future data sets that will help lift the flat directions found when analyzing Drell-Yan data at the LHC. We also point out the importance of accounting for dimension-8 effects in fits to Drell-Yan data by showing that they can significantly impact bounds on dimension-6 Wilson coefficients.