  We examine the consequences of the effective field theory (EFT) of dark
matter-nucleon scattering for current and proposed direct detection
experiments. Exclusion limits on EFT coupling constants computed using the
optimum interval method are presented for SuperCDMS Soudan, CDMS II, and LUX,
and the necessity of combining results from multiple experiments in order to
determine dark matter parameters is discussed. We demonstrate that spectral
differences between the standard dark matter model and a general EFT
interaction can produce a bias when calculating exclusion limits and when
developing signal models for likelihood and machine learning techniques. We
also discuss the implications of the EFT for the next-generation (G2) direct
detection experiments and point out regions of complementarity in the EFT
parameter space.
