14. The hardware computer-readable storage media of claim 13 , wherein: comparing the refined search queries to the first seed query comprises employing a click graph to determine first similarities between the multiple first refined search queries and the first seed query, and comparing the refined search queries to the second seed query comprises employing the click graph to determine second similarities between the multiple second refined search queries and the second seed query.
13. The hardware computer-readable storage media of claim 12 , the acts further comprising: identifying a first seed query associated with the first topic and a second seed query associated with the second topic; comparing the refined search queries to the first seed query to identify the multiple first refined search queries associated with the first topic; and comparing the refined search queries to the second seed query to identify the multiple second refined search queries associated with the second topic.