This is a good opportunity to remind pupils of your school's policies on bullying and reinforce any of your initiatives, such as a "bullying box" for children to leave notes in confidence.
After that, it's good to remind pupils what constitutes bullying rather than accidents or thoughtlessness, make clear that certain behaviour is unacceptable and also that bystanders have a responsibility to report incidents.
You could talk through various scenarios and get the children to vote on whether or not they are examples of bullying. What constitutes a bully - is it someone who is aggressive more than once, or is it a one-off incident?
You could also show photographic examples of bullying and ask the pupils to talk about how each person portrayed might feel. What about the bully? What about the victim?
Help, I've got no time to prepare
There are PowerPoint presentations for assemblies for ages 5 to 14 at www.beyondbullying.com.
Where can I go for more information?
See The TES Magazine's features on bullying - both at pupil and management level - next week.