“Here’s my poster for the Society for Neuroscience Meeting!”
“Looks nice, but where’s the rest of your data?!?”
“I chose not to include it, you don’t want to give away the whole package, otherwise nobody is going to read the paper.”
“Because everyone who could possibly see your paper will be at the meeting and at your poster?”
“Yea, potential reviewers will not get excited about it because they will have already seen it.”
Oy. I don’t know where that particular misconception arose, but it really took me by surprise. And I think that it stems from a fundamental misunderstanding of what a poster is for. First off, it is not a press release, or pre publication. Rather it is a chance to present your work and get your colleagues excited about it. A chance for you to stand by your work and make it shine, to show others why you think what you do is cool. A poster is also a chance to get feedback on your work from your colleagues, the more data you show, the better the feedback. It gives you a chance to try and pitch your story in different ways so that you can find the most efficient, clear and logical way to get your point across. To see what works and what doesn’t. And every time you give your little spiel to someone else, you get a little better at telling it, so that when you get home and start writing your paper, you’ve got your work cut out for you. So don’t skimp on your posters, make them good, and you’ll get much better returns!
Take it to the Bridge 
Wow, I can’t imagine why it would be better for someone to read the paper…at the poster when they are critical you can defend yourself, but when someone is reading your paper there is no such recourse.
is it more about not having the reviewers be excited, or the fear of being scooped
As I’ve written before, it’s pretty hard to get totally scooped on a multifaceted project: http://scientopia.org/blogs/bridgeblog/?s=scoopage