According to a CNET article, a Journal of Personality and Social Psychology often misinterpret the tone of email messages about 50% of the time and believe they have correctly interpreted it 90% of the time.  This just goes to show how careful we must be as both readers and writers of communications.  As writers, we must take the extra step and try to clarify even seemingly obvious ideas.  As readers, we must try to put ourselves in the writers position and give them the greatest benefit of the doubt.  I can’t count the number of times I’ve been misunderstood or that I’ve seen people on the same side of an issue start arguing over some percieved ‘tone’ of voice.