There  has been   a recent documentation change on how to filter search results  based on Authoring templates

Prior documentation had indicated using the + character   when specifying  the authoring template  within the scope  document 

+AuthoringTemplate::"TEMP-Article" 

    

 

It should be  ^   character instead .    So specifying search results  on  authoring  template  TEMP-Article  will be accurately represented as follows
   ^AuthoringTemplate::"TEMP-Article" . 

 

More  comprehensive  scenario and  examples  can be found here
Filtering search results    http://www-10.lotus.com/ldd/portalwiki.nsf/dx/Filtering_search_results_wcm7