A common question:

I want to contribute to Public Lab -- should I post a research note or a wiki page?

And one possible answer:

If in doubt, just go ahead and write a research note. You can always copy it into a wiki page later.

What's the difference?

Research notes are just like a blog. You are the author, and they have a publication date. They can be informal -- just a photo or a link -- or regular updates on your research progress.

Wiki pages are collaborative documents. They're more formal and complete descriptions of projects, instructions, or anything structured you want others to be able to edit and correct.