Most bodybuilders believe that, like legs, the back is a complex muscle group, and therefore requires a higher volume of sets in order to properly stimulate the muscles into growth. They split back day into muscle groups, then train each muscle group as if it deserved its own day. An example of a high volume back day is as follows.

Lats
Chins 4 x 10
Lat pulldowns 4 x 10
Barbell rows 4 x 10
Low cable rows 4 x 10

Lower back
Deadlifts 4 x 10
Hyperextensions 4 x 10

This makes back day a 24-set day, which is considerably more than most athletes can tolerate without either reducing the intensity to handle such a 75-minute endeavor, or risking injury or overtraining. Many people, when faced with the daunting task of targeting a single area with that many sets, will subconsciously reduce weights or reps used, reasoning with themselves that they have to leave something in the tank for the next hour-plus of training. Additionally, they might try to convince themselves that it’s acceptable because ‘with all these sets I’m doing, surely I’m making it up somewhere!” Alternatively, some beginning and intermediate bodybuilders will attempt to sustain full intensity for 24 work sets on back day. When this happens, they often find themselves becoming injured. Remember that the human body wasn’t designed to lift weights. It grows as a result of exposure to moderate to fairly intense weight training, coupled with food and rest. The joints, however, are not as adaptive as the muscle groups are. Twenty-four sets of jarring weight training can lead to repetitive stress disorders, or worse, something tearing.

So is high volume back training is the only way to go? No. A growing number of bodybuilders feel differently. They believe that only so much stimulation can be attained by the back. They believe that after so many sets, the arms begin doing the brunt of the workload. They feel that we short-circuit our efforts, reduce recovery abilities, and run the risk of injury by training in such a haphazard manner. They feel that maximum intensity can be achieved using a much smaller workout routine. An example would be something like this.

Lats
Chins 2 x 10
Lat pulldowns 2 x 10
Barbell rows 2 x 10

Lower back
Deadlifts 3 x 10
Hyperextensions 2 x 10

See which way works for you. The solution may lie somewhere in the middle. As long as you are sustaining maximum intensity and completely working the muscle group without overdoing it, you will find success!