  The amount, timing and ultimate location of mass transfer and induced star
formation in galaxy collisions are sensitive functions of orbital and galaxy
structural parameters. I discuss the role of detailed case studies and describe
the results for two systems, Arp 284 and NGC 2207/IC 2163, that have been
studied with both multiwaveband observations, and detailed dynamical models.
The models yield the mass transfer and compressional histories of the
encounters and the ``probable causes'' or triggers of individual star-forming
regions.
