Final-State Interactions in Nonleptonic Hyperon Decay

We discuss the consequences of including the final-state interactions in the analysis of ${\Lambda }^0$, $\Sigma$, and $\Xi$ non-leptonic decays. Emphasis is on the role that the final-state interactions play in tests for $T$ invariance, in tests of the $\Delta I=\frac{1}{2}$ rule (including the resolution of sign ambiguities), and in the determination of the decay amplitudes for these processes.