CREATE TABLE table_31007 ("No. in series" FLOAT, "No. in season" FLOAT, "Title" TEXT, "Directed by" TEXT, "Written by" TEXT, "Original air date" TEXT, "U.S. viewers  ( millions ) " TEXT)

How many people wrote episode 9 in the season that was directed by Ernest Dickerson?
SELECT COUNT("Written by") FROM table_31007 WHERE "Directed by" = 'Ernest Dickerson' AND "No. in season" = '9'
SELECT COUNT("Written by") FROM "table_31007" WHERE "Directed by" = 'Ernest Dickerson' AND "No. in season" = '9'