  The dispersion and mean trends of r-process abundances in metal-poor stars
are discussed based on a model of diverse supernova sources for the r-process.
This model is unique in that its key parameters are inferred from solar system
data independent of stellar observations at low metallicities. It is shown that
this model provides a good explanation for the observed dispersion and mean
trend of Eu abundances over -3 < [Fe/H] < -1. It is also shown that this model
provides a means to discuss r-abundances in general. For example, the Ag
abundance in any metal-poor star with observed Eu and Fe abundances can be
calculated from the model. This approach is demonstrated with success for two
stars and can be further tested by future Ag data. The dispersion and mean
trend of Ag abundances in metal-poor stars are also calculated for comparison
with future observations.
