user: Question: Who directed episode number 3?
Columns: ['Episode No.', 'Title', 'Directed by', 'Written by', 'Original air date', 'Production code']
Types: ['real', 'text', 'text', 'text', 'text', 'text']
Sample row: [1.0, '" Serenity "', 'Joss Whedon', 'Joss Whedon', 'December 20, 2002', '1AGE79']
SQL:

assistant: SELECT "Directed by" FROM "Table" WHERE "Episode No." = 3.0;