CREATE TABLE table_23411 ("No. overall" TEXT, "No. in series" FLOAT, "Family/families" TEXT, "Location ( s ) " TEXT, "Original air date" TEXT)

Name the family for uk31
SELECT "Family/families" FROM table_23411 WHERE "No. overall" = 'UK31'
SELECT "Family/families" FROM "table_23411" WHERE "No. overall" = 'UK31'