Proper direction when installing slotted rotors?

[SyberTiger]

I'm installing new rotors and pads on my 2002 Explorer. The new rotors are slotted. The driver side rotor is different than the passenger side in that the slots run down from left to right (like this "\" symbol) whereas the other side the slots run up from left to right (like this "/" symbol). Essentially, the rotors are mirror images of each other. The question is: which side is supposed to get which rotor. They are not marked "right" and "left". I've had at least one person say "it doesn't matter" and it doesn't affect performance. That seems odd in that they look like they are unidirectional.

 

[JohnnyO]

If you look at, say, the 12 o'clock part of the rotor (either side), the slot should be pointing down and forward.
If somebody thinks it doesn't matter, then picture the rotor spinning forward and which way do you think will clear the brake dust better?

 

[SyberTiger]

I think you are saying that...looking at a slot on the rotor at the 12 o'clock position the slot should look like this /

Does it matter if the brake pad and associated caliper is sitting at the 3 o'clock position or the 9 o'clock position in regards to the issue of clearing out brake dust the best.

I think you are saying that due to centrifugal force it is better to have the slots going in this / direction instead of this \ direction because it spins the dust outward more efficiently.