Observing the structure of the interstellar clouds

We discuss some methods for characterizing the mass distribution in the interstellar clouds. This is done in the light of available observational techniques and of appropriate statistical tools capable to highlight the structural properties of the astronomical images. The potentialities of the optical and near-IR imaging of dark clouds as well as of their far-IR and millimetric mapping are also discussed with respect to the analysis in terms of statistical characterization. We briefly address the hypothesis that the origin of the structure observed in interstellar clouds is the turbulence which could be a natural consequence of the physical status of the interstellar medium. We finally discuss how the fractal geometry offers an interesting tool for characterizing the structure of the interstellar clouds introducing the so called multifractal spectrum. The physical interpretation of this spectrum can offer a further tool in discriminating among different possible kind of internal dynamics