This is the most delicate task. The information is stored in two main files: rosen_multidim.out and rosen_multidim.dat. The file dakota.rst is used for restart a previous simulation.
Below is an extract from rosen_multidim.out. After evaluating the model response of on the parameter grid points, a brief summary of the most important statistical values is reported:

In many cases, some Python scripting can be useful for visualizing the results.
Below is the theoretical surface of the Rosenbrock function and the wireframe discretization of the multidimensional parameter analysis.