When you say "research experience". . . .

[BeingThere]

I am wondering if there is a qualitative difference (for purposes of assessment by an admissions committee) in independent research (Honors thesis or independent research project where the student is the PI) versus working in a lab or working as a research assistant on a project initiated and headed by a professor or graduate student.

I've got four independent research projects (three completed, one in progress) and one semester as a research assistant for a professor in which I conducted a literature review. My independent projects have led to posters, presentations, and one is being written up to be submitted for publication.

Will the fact that I haven't worked on larger or "more important" research projects with faculty be considered a negative, even though I have a good amount of independent research?

Do admissions committees give more weight to one type of research experience than another?

[psychsquirrel]

Admissions committees just want to see that you are fully capable of conducting research. It sounds like you have great research experience

[CBrown]

If you have something that is becoming a manuscript for a publication, that is the biggest thing on your list. Doesn't matter what it is, sounds like you have a strong research profile. An honours thesis is a universally recognized way of stating you spent eight or more months on an independent research project, but you have more than that, so don't worry about the actual honours aspect. Most programs state 'honours degree OR equivalent' and your experience seems more than equivalent. If you are concerned, you can always contact specific programs' admission offices to get their perspective as well.

[SocialConstruction]

In line with everyone else's responses, your research experience sounds excellent. I've also heard from my advisors and graduate student mentors that self-directed research can be more impressive than simply helping out in a lab. Regardless, you've got both so you should be a stellar candidate to I/O programs.