The default metrics for props is page views and the default metric for evars is instances. However, for non-seasoned SiteCatalyst users, this can be a tough one to explain. For example, you show internal search terms have 500 page views. This doesn't make sense to the user. But those that have used it know that the specific search term was searched 500 times.
Each report should be able to have this default metric renamed. For the internal searches report, it would be something like "Searches", that way the user can easily identify the metric.
This feature would be a setting for each individual report.