I study the large-scale processes and global effects of massive star formation in galaxies, primarily using infrared observations.
1) Ultraluminous infrared galaxies (ULIGs)-starbursts vs. AGN; the initial mass function in ULIGs; ULIG evolution
2) Massive star formation in super star clusters-Milky Way objects such as W51 and W49 as analogues of distant clusters; the IMF in such clusters
3) Infrared diagnostics in evolutionary synthesis models of starbursts- fitting the entire UV/optical/near-IR/far-IR spectrum of NGC 7714 with a single starburst model; adding new spectral features to starburst models.