user: Question: Who wrote the episode whose director is Karen Gaviola?
Columns: ['No. in Series', 'No. in Season', 'Title', 'Directed by', 'Written by', 'Original air date', 'U.S. viewers (millions)']
Types: ['real', 'real', 'text', 'text', 'text', 'text', 'text']
Sample row: [40.0, 1.0, '"Glass Houses"', 'Tucker Gates', 'Molly Newman & David Marshall Grant', 'September28,2008', '12.35']
SQL:

assistant: SELECT "Written by" FROM "Table" WHERE "Directed by" = 'Karen Gaviola';