Shield or no shield with dagger?

I read somewhere once that if you use daggers/are a rougish class then you're better off using no shield than with since evasion is better with light armor + no shield.. Is this true?

Yes, do not use a shield with a dagger. You need evasion more than pdef if ur rolling a dagger. Or at least thats just my opinion.

A shield bestows a -8 upon evasion, which you need as a light armor user.
Several buffs like Song of Water (SWS), Agility (EE) and Chant of Evasion (WC) enhance your evasion further as does a +DEX Tatoo or certain types of armor (Zubei light).

There was a certain discussion about Daggers should carry a shield in case they would encounter an archer they couldn`t outrun...given the fact that you do not get shield masteries and bonus fro heavy armor sets like Avadon or Doom Set and are furthermore not likely to have things like Bless Shield being cast on yourself I consider this idea to be of little value.

Plain and simple, dont use a sheild, ever.

Heavy Set + Shield only if you plan to 1 vs. 1 in a dagger vs. dagger PvP, for any other PvP take light set and no shield 'cause it eats your evasion!