Raids & exp

How does raiding affect ones experience?
I am of the idea that when defeating a contestant within a raid this negatively affects your exp.
When you defeat a player in a regular fight you see in the report a positive number on the last line. When defeating a contestant within a raid it shows a negative number on the last line of the report.
Could someone clarify.

The number you see is a respect value. Normal attacking gives a positive value - it gains your faction respect. Raiding only reduces your opponent faction's respect, hence the negative value.

The XP you gain for any attack is completely separate from this value, and is always positive and always the same no matter what warring type.

Its best not to mug a defeated player to increase your exp. If you leave the defeated player your exp is slightly higher. but you wont get the cash.