Wondering if doing this has helped anyone here -- many of my site's pages are in the Supplemental Results index and I'd love to hear from anyone who can share their experience in getting them out. Thanks!
I can't see submitting a sitemap to Google doing anything in this situation. Just by being in the supplemental index, Google acknowledges that they know about them
Building good backlinks is the best way to get your pages out of supplemental. One of the reasons cited for putting pages in the supplemental result is Google doesn't have too much confidence in your site. Quality backlinks is the solution for that.
backlinks to the sup pages are one of the only things you can do to get them out. submitting a site map wont do what you want it to.
As has already been said a XML sitemap will not help you. Creating a html sitemap so Google has links to all the pages can help some but probably won't get them out of the supp index. You need some good quality backlinks to those pages. Also try linking from your home page to the supp page. It will usually do it if your home page has any kind of value.
Make sure that the content on each of these pages is unique and that they aren't getting caught by any dup filter. After you have changed the content, submit the sitemap with only your unique pages and you will get out. This has happened to me before and I was able to successfully correct it. You might be in the supplemental index for other reasons, like you site being new or having few back links, in that case just keep working on your promotion and it will come right.
I really appreciate the helpful tips you guys have all provided -- going to work on incorporating them into my site now.