It is well established that enhanced star formation (starbursts)
 can be induced by galaxy-galaxy interactions. One manifestation
 of this activity is enhancement of the IR emission from such
 pairs. Galaxy mergers and closely interacting pairs often show
 large increases in IR/optical emission. While the phenomenon of
 starburst enhancement is well established, the details are not at
 all clear (both components? nuclear and/or disk enhancement?).
 IRAS was incapable of unambiguously answering these questions
 while ground based (and KAO) observations suffer from low
 sensitivity. The most serious current deficit is our lack of
 a clear physical understanding of the physical mechanism(s)
 for starburst enhancement.

 We propose to learn more about the enhancement process by
 observing a sample of pairs that are typical of the ones showing
 the strongest star formation enhancement. The outstanding
 sensitivity and much improved angular resolution of ISO offer a
 unique opportunity to resolve the details of the phenomenon and
 to gain an insight into the physics of the process.  Our sample
 involves close spiral pairs with overlapping (most appear to be
 colliding) disks (10 autumn or 11 spring launch). The proposed
 observations of MIR/FIR emission and color ratios will provide
 strong constraints on models for the time evolution and spatial
 distribution of interaction induced star formation. The ISO data
 will be combined with observations obtained by our team at other
 wavelengths.