Spectroscopic and spectropolarimetric observations of the diffuse interstellar medium

In this thesis we describe a variety of observations aimed at illuminating the structuring forces that dominate small molecular clouds in the diffuse interstellar medium. Decades of existing observations indicate that interstellar turbulence, magnetic fields, or, more likely, a combination of the two are responsible for the structure and formation of these objects. We present spectroscopic and spectropolarimetric observations as contributions to a comprehensive analysis of the effects of these forces on three high-latitude molecular clouds (HLMCs) and one intermediate-velocity molecular cloud (IVMC). Specifically, we take the first steps toward investigating the virial state of these clouds, including an investigation into the extent of interstellar turbulence in the IVMC, and a preliminary look at the strength of the line of sight magnetic field component for all of these objects.