Absorption and scattering coefficients of surfaces are crucial components of room-acoustic simulations. The random-incidence scattering coefficient is the most uncertain metric applied in geometrical acoustics. Databases of scattering coefficients are rare. Their impact on auditory perception in auralizations, however, is relatively well studied. Research directions in developing improved scattering metrics can focus on their relevance for auditory effects, their influence on the spatial sound energy flow, their characterization in angular decomposition, and their estimation with simple rules of thumb. This paper will highlight the state of the art in determining and using scattering coefficients, and it will discuss possible improvements.