  Gravitational wave observations will be excellent tools for making precise
measurements of processes that occur in very strong-field regions of spacetime.
Extreme mass ratio systems, formed by the capture of a stellar mass body
compact by a massive black hole, will be targets for planned space-based
interferometers such as LISA and DECIGO. These systems will be especially
powerful tools for testing the spacetime nature of black hole candidates. In
this writeup of the talk I gave at JGRG19, I describe how the properties of
black holes are imprinted on their waveforms, and how measurements can be used
to study these properties and thereby learn about the astrophysics of black
holes and about strong-field gravity.
