I am creating a web site that will allow the users to determine the
quality of articles. Users will also have the ability to filter the
articles that they are shown based on the quality of the article.

So far, the two options that i see are to
  1) Allow the users to vote either "yes" or "no" to an article, based
on whether they like it / thought it was helpful / etc.
  2) Allow the users to rate the article on a scale system (1-5, 1-10, etc)

My question is which of these methods would be most useful to the
users? I would like to know if any studies have been done on trends
using rating systems and which are most acurate.

I need to convince my boss of one of the options, so the more data
that i have to back it up the better... I will leave a tip for a great
answer!

Before I put my thoughts in, I will be the first to admit I am not a
mathmatician or statistics guru, although I did quite well in both in
college.

I have done a similar rating site for an intranet application for a
larger company and we decided on using a scale on of 1-10. There were
many factors to consider depending on how accurate you need your data
to be.

The argument for having a scale of 1-to-10 instead of 1-to-5 or even
using yes/no (which is really the same as having a scale of 1-to-2),
is really for what degree of accuracy is needed to rank the quality of
an article. There are a few factors that come into play....

1) The more articles there are, the more meaningful a wider range will
be so that many articles do not have the same rankings and therefore
can be properly ordered on its usefulness.

2) The more votes casted for a group of articles, the more accurate
the rating, since you are representing a larger portion of the
population with each added vote.

With these 2 factors, it would seem logical that there is a
relationship between number of voters and number of questions. The
more articles that need to be accurately ranked, then larger the scale
needed. The more votes you expect to get, the more accurate the
results, and therefore a smaller scale would be needed.

Now the practical side...if it takes the user the same amount of time
to answer yes/no as it does to answer 1-to-10 or 1-to-5 rating, why
not go for the 1-to-10 since it will have a wider range of
measurability and will give your rankings a much less ties?

In closing, don't reinvent the wheel....here are a few random sites I
picked that have similar rating systems at the bottom of their pages.
The are all slightly different but you might get ideas based on their
target audience and business areas.

1) http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnnetsec/html/THCMCh18.asp

2) http://www.booksamillion.com/ncom/books?id=3200073236302&pid=038551428X

3) http://www.15seconds.com/issue/040614.htm#rate
   --Search for "Rate This Article" on this page.

Hope this helps ....