Google penalizes site with thin content. Q&A sites run by any platform is prone to have pages with so called thin content.
Best way to ensure you are not hit with Panda Penalty is to ensure minimal thin content (
http://searchengineland.com/5-new-tactics-for-seo-post-panda-73982)
Attached code when pasted onto custom theme (qa-theme.php) helps to minimize Google Panda Penalty be ensuring that pages with thin content are not indexed. Of course, it is possible that code can be more efficient, seasoned developers please feel free to modify the attached code
function head_metas()
{
switch ($this->template) {
case 'question':
$ansnum=$this->content["q_view"]["raw"]["acount"];
//Pages with zero answers should not be indexed
if ($ansnum==0) {
$this->output ('<meta name="robots" content="noindex,nofollow">');
break;}
// Other question pages - default behaviour
if (strlen(@$this->content['description']))
$this->output('<META NAME="description" CONTENT="'.$this->content['description'].'"/>');
if (strlen(@$this->content['keywords'])) // as far as I know, META keywords have zero effect on search rankings or listings
$this->output('<META NAME="keywords" CONTENT="'.$this->content['keywords'].'"/>');
break;
case 'tags':
// Tags page is more like sitemap
$this->output ('<meta name="robots" content="noindex,follow">');
break;
case 'users':
// Users page is more like sitemap
$this->output ('<meta name="robots" content="noindex,follow">');
break;
case 'tag':
$r = count($this->content["q_list"]["qs"]);
//If there is only two questions for the tag avoid indexing it
if ($r<=2)
$this->output ('<meta name="robots" content="noindex,follow">');
break;
case 'user':
//if there is no activity by user do not index it
$r = count($this->content["q_list"]["qs"]);
if ($r==0){
$this->output ('<meta name="robots" content="noindex,nofollow">');
}
break;
default:
if (strlen(@$this->content['description']))
$this->output('<META NAME="description" CONTENT="'.$this->content['description'].'"/>');
if (strlen(@$this->content['keywords'])) // as far as I know, META keywords have zero effect on search rankings or listings
$this->output('<META NAME="keywords" CONTENT="'.$this->content['keywords'].'"/>');
}
}