I would like to know what are the parameters that I have to take into consideration before deciding whether I should incorporate to a website a Q&A system or a traditional forum ?I think forums allow better search capabilities (you can easily dig out old posts) over the Q&A system, but the latter offer simpler / faster interaction between the users and the site owners.I should add that only a few people (site owners + authorized people) could answer the questions, the user will be on a read-only basis.Anyone can help me decide between the two solutions ?Thank you in advanceNB: There is also the impact on the SEOs, are they the same for forums and Q&A systems?    
Forum vs Q&A system
seo;forum;qa
Here are the answers I found online:On Q&A systems:From David Givoni,bCofounder of Answerbase.com, a Q&A platform service. Extracted from his answer on (quora.com) (you need to register to see the full post)Q&A system:are focused on problem solving  motivates through a point systemmore user friendlyFocused on problem solving  Where a normal forum lends itself to long discussions and exchange of opinions the Q&A system is more  focused on solving problems.On social Q&A sites the user who asks a question has a problem that  needs a solution and the users who responds are other users with an  expertise to help solve that problem. The answers are rated, the best  get rewarded and for future users its easy to see what the solution  to the problem was, since the best answer is highlighted. And when the  solution has been reached the question is closed. There is also a race  to get first with the right answer, since the first correct solution  is normally the one rewarded.So for users that are looking to solve an issue, Q&A systems are an  excellent tool for doing that.Motivates through a point system An expert on a Q&A site is able to earn points by answering questions quickly and correctly and since  the questions are associated with specific categories, so the expert  gains category specific points that can be used as a measurement of  the experts knowledge and ability to share it.Q&A software is more user friendly And since best answers are highlighted, the question has a status that indicates whether its  been solved or not and since there is no paging or threaded  discussions, its easier especially for future users to reuse the  information given.On Traditional ForumsFrom: Sanjay Sabnani,I run a public company that owns, acquires, and operates forums. I also have over 75,000 forum posts across several forums since 1999Extracted from his answer on the same post as above (quora.com). Also extracted from his answer Forums on the other hand allow for a much greater degree of interaction because the members can not only ask questions, but share experiences as well.  Asking and sharing are terms that pretty much sum up the entirety of experiences we encounter on the Internet so in this way forums are a much more ubiquitous platform for reaching out to your stakeholders.  Levels of engagement is much higher because members are allowed a voice even when they do not have something that critical to add.And about SEO being boosted by Q&A systems here is an in-depth analysis on their impact on a website --> seomoz.org: 6 Reasons Why Q&A Sites Can Boost Your SEO in 2011Bottom line, Q&A is what I need