Relaying negative feedback can be helpful. But also relaying positive feedback is also important. Negative feedback should be given only to the person who it is for. And not discussed with other members of the staff. Also give a solution on how to turn negative feedback into positive feedback. Set goals for the future to improve the performance. And then give feedback that is positive. I like to think encouraging others is better and beneficial. 

Effective communication is very important. The way you communicate with a person can break or make your relationship with your employee. Effective communication involves one on one communicating. If you choose not to communicate appropriately then the person that the information is attended for could look at your lack of communication skills as a insult. Effective communication means a a lot in team building and relationship building.