CREATE TABLE table_73579 ("No. in Series" FLOAT, "No. in Season" FLOAT, "Title" CLOB, "Directed by" CLOB, "Written by" CLOB, "Original air date" CLOB, "U.S. viewers  ( millions ) " CLOB)

Who wrote the episode whose director is Karen Gaviola?
SELECT "Written by" FROM table_73579 WHERE "Directed by" = 'Karen Gaviola'
SELECT "Written by" FROM "table_73579" WHERE "Directed by" = 'Karen Gaviola'