Feedback that is going to make a difference has the following ingredients:
what you say is true, (it’s a fact, not your opinion i.e. it’s first hand experience not something you heard from someone else);
it is succinct (if you’re not clear enough to be succinct, find someone to talk to and get things clear in your mind first);
it’s about someone’s observable behavior and is something which they could change i.e. it’s not something about them personally that they can’t change;
you give a recent example of what you’re talking about;
you deliver it direct to the person or people whom it concerns, not to third parties;
you give your feedback at a suitable time and place (e.g. when you’ve got time to follow up if you need to. Positive feedback can be given when other people might be able to hear. ‘Could do better’ kind of feedback should be done one to one.)
If you implement these simple guidelines the next time you are giving feedback you will find your input is a lot more to the point and valuable.
Think Productive UK also offer a workshop in Fixing Meetings.