yep, "Impact Factor" (IF) is the term, and (just to clarify) it encourages but does not force. there are open access journals like PLoS w/ significant IF, albeit not comparable to Nature.
since the link below was written, PLoS has become not only open access for articles but also open access for the data those articles are based on. imo, open access to data (w/ privacy measures, of course, for human subjects) is of the same order of importance as access to articles.
since the link below was written, PLoS has become not only open access for articles but also open access for the data those articles are based on. imo, open access to data (w/ privacy measures, of course, for human subjects) is of the same order of importance as access to articles.
http://scholarlykitchen.sspnet.org/2013/06/20/the-rise-and-f...