For each mission in CSI, you get 5 statistics:

* Evidence Collection
* Hints Used
* Case Total
* Ranking
* Extras

The first three are percentages and keep track of how much of the game-world you figured out. Did you find all the bits of evidence lying around? Did you have to use any hints in order to progress? Did you fully solve the case? Try to play each level with NO hints and finding every last little clue.

Ranking is just a "title" that you earn for how well you do.

You earn extras for how well you do on each level. They are character and location sketches done by the artists, just a fun tidbit.

CSI Crime scene Investigation Walkthrough