If you are experiencing high bounce rates that is a good sign your pages or content are either low in quality or poorly designed. Specifically it might be:
Poor content If your content isn't high quality users will know (by not finding what they are looking for or not feeling confident in your data) and go look for another website that offers better information.
Poor usability If your pages are hard to use because the content is cluttered, features are hard to find, colors are harsh on the eyes, etc, then users will leave and go look for another website to find what they are looking for.
Poor navigation If it is difficult to navigate your website then obviously users will find it hard to visit multiple pages.
Slow loading pages Google is pressing the idea of faster websites to webmasters for a reason. The evidence clearly shows faster pages mean higher conversions and slower pages mean lost conversions.
Users don't find what they are looking for If you try to optimize your pages for one thing, but the page really is about another, then users will be disappointed when they find the page doesn't have the content they were looking for.
So obviously what you want to do is:
Make sure your page is clean (not cluttered) and pleasing on the eyes.
Make sure your content is unique and high quality
Make sure the page titles, meta description (since it may be shown in Google's search results), headings, etc, all accurately describe what the page's content is about
Make sure things like logins and site navigation are easy to find and use.
Make sure your pages load quickly. Here are some tools and ideas for doing thatHere are some tools and ideas for doing that.
