query: SELECT title FROM course WHERE dept_name  =  'Statistics' EXCEPT SELECT title FROM course WHERE dept_name  =  'Psychology'
question: What-all titles alla course Statistics a department which not A Psychology a department?
query_toks: SELECT title FROM course WHERE dept_name = 'Statistics ' EXCEPT SELECT title FROM course WHERE dept_name = 'Psychology '
query_toks_no_value: select title from course where dept_name = value except select title from course where dept_name = value
question_toks: What-all titles alla course Statistics a department which not A Psychology a department?