Should you expose differently for raw?

Dynamic range

You can expect to recover up to 1EV extra highlight detail from a Raw but up to 3-4EV from underexposed areas. Keep this in mind when shooting high-contrast shots and expose for the highlights. Think about the processing you may do later, don’t just pick settings that look ‘right’.

Your histogram will lie!

The histogram on the back of the camera is not displaying your Raw file, but a JPEG preview generated by the camera on-the-fly. It only shows you what a JPEG would look like, not the Raw data itself. The Raw file will usually contain more highlight and shadow detail than the histogram suggests.

Expose to the right?

This means increasing the exposure to push the histogram as far to the right as you dare without clipping the highlights. The quality is said to be better, in theory, but it’s risky and means extra processing work later, so it’s probably not worth it unless you have the time to experiment.