Betty's statement is generally true, but there are rare exceptions.
This year I've hived 42 swarms and 2 of them settled into the box nicely the first 
day, only to abscond  hours later the same day, or the next day.  In one case I 
put them back in the same box and then they stayed.  The other one took off across the countryside and I lost track of it when it crossed a creek.  In both cases, the queen was in the box.
 
A frame of brood in all stages of development will generally keep a swarm in a box even if they don't particularly like it.  Problem is, I don't always have a spare frame of brood handy when hiving a swarm.
 
 
If a swarm does not immediately leave the hive box, it has adopted it as a
new home.  If the queen has not entered, the entire swarm will leave again
within 5 minutes.