On or shortly after August 24th, we will remove the 
BROAD_SESSION match type label from the 
MatchType column in the 
Search Query Performance and 
Paid & Organic Query reports. Instead, rows that formerly returned "broad (session-based)"  will begin returning "broad".
To simplify the way we report on match types, this label will be removed from all of our reports, including historical reports. If you'd like to see how your keywords are currently matching to this label, download a copy of your Search terms report before 
August 24th, 2015.
This is a reporting change and will have no impact on the 
broad match serving behavior. You can learn more about the 
MatchType column in the 
AdWords Help Center.
As always, if you have any questions, comments, or concerns, please contact us via the 
forum or the 
Ads Developers Plus Page.
- Michael Cloonan, AdWords API Team