Creating model to batch select polygons by attribute and merge them together

Question

Is there is a way to create a ArcGIS 10 MODEL to:

1. batch select polygons from the same layer by attribute
2. merge these polygons into one
3. repeat this for all polygons shearing the same attributes

example: To create a geological map with all mapping polygons merged into one big polygon of the same lithology.

Answer 1

This is a job for the Dissolve tool.