HI and star formation in nearby dwarf irregular galaxies

Dwarf irregular (dIrr) galaxies are not just small versions of spiral galaxies. They are gas-dominated but with low gas density overall and with thick disk structure and high gas porosity. These properties have consequences for the formation of clouds that produce new stars. Yet, young stars can be found not only in the central regions of dIrrs, but in their far outer disks where gas densities are very low. I will discuss four possible drivers for cloud formation in dIrrs and the complications with each in explaining the star formation found in typical, isolated dIrrs.