INTRODUCTION Measurements in the molecular frame help elucidate the fundamental physics of molecules. The physics of molecules in turn inform the nature of interaction between a number of quantum particles, important for both the understanding of larger systems and that of fundamental quantum phenomena. Measurements made in the laboratory frame from randomly oriented molecules, or a thermal mixture of numerous angular momentum states, result in a loss of information due to incoherent averaging over the orientations, or equivalently, the rotational states. Methods to overcome this either coherently drive a large number of rotational states, or select the ground rotational state from an ensemble. Either scenerio results in spatially anisotropic distribution, with the former approaching the molecular frame as the distribution of rotational states broadens. This is the preferred method in ultrafast physics, since the time resolution allows for measurements at the moment of sharpest alignment. The latter method is typically applied for precision spectroscopic measurements. Recent advances in laser cooling of di- and tr-atomic linear molecules has enabled coherent selection of the ground rotational state, allowing for precise spectroscopic measurements of dissociative molecular states.