Constraining dynamical models with observational data

The spatial distribution and kinematics of stars in the Milky Way are linked through the gravitational potential. Observations of the positions and velocities of stars can therefore be used to measure the mass distribution of the Milky Way. I review steady-state dynamical modeling approaches and illustrate their use in constraining the local matter distribution and the circular velocity curve from the kinematics of stellar tracers. In a few years, Gaia will increase the number of precise positions and velocities by multiple orders of magnitude. I describe some of the dynamical analyses that will be possible with the Gaia data and discuss some promising avenues for the optimal analysis of dynamical data.