A few weeks ago, I was showing a teacher SMART Notebook’s Shout it Out. He loved it and right away had the students posting their math problem solutions and explanations to the SMART board.
What he discovered was that some students waited to see what others posted before sending their answers. To protect those students who were not as competent, he turned off the ability to display contributor names. Then in a moment of inspiration, he used the screen shade to hide what appeared on the board until all the students had posted. Once all had submitted their answers, he closed the screen shade and revealed the answers. Since I saw this, I have used this strategy many times.