In my Tang Soo Do school, we begin sparring at orange belt level, if we have purchased our sparring gear. It takes about four months to get to orange belt.
Meanwhile, as white and yellow belts, we do one-on-one kicking drills two weeks out of the month.
We do have sparring classes but only black belts or those in black belt club can join sparring classes. Sometimes people are invited to join Black Belt Club at white belt if they are mature and motivated.
I've seen schools use a variety of approaches. Some, like the Kyokushin schools, let their white belts do full contact free sparring. Others might not even let their people free spar until they hit brown belt of higher. One system may say "it's better for them to experience free sparring early, so their techniques can get better from it," while another many say "it's better to wait until their techniques are refined enough."
You know what? It works both ways, provided that the teacher knows what he's doing, and provided that the students listen. Now, some students are going to do better in one situation than another. To each his own.
I prefer letting people wait until they've at least started their intermediate classes (10th-8th kyu white and yellow belts are in the beginners class, 7th-4th kyu orange through blue belts are intermediate students, 3rd kyu brown and up are advanced). At this point, their fundamental techniques are usually refined sufficiently.
Even then, their first few sparring sessions are going to be against senior brown belts, or even the black belts, who are there to act as mobile targets that put up a simple defense. As the student grows more experienced, the mobile targets then start offering some simple attacks. Eventually, we start pairing the students up against similarly ranked students, under the direct watchful eye of the instructors.
I prefer this method, since it gradually builds up confidence in the students, and there's fewer injuries along the way.
I think it depends on how large the class is and how many instructors are available to supervise. Free sparring is good but at the lower belt ranks, technique is more important, IMO. It is important that they get an accurate impression of what the technique is supposed to do and what it feels like when it's done in a contact situation. If the sparring can be individually supervised, I say let 'em go. Stop to make reccomendations. From day one if possible.
From day one. The children (who do wear sparring gear) already know how to spar lol, they've all watched Ninja Turtles, Power Rangers etc! and before they have their first sparring sessions they can't be told anything lol! After that we start teaching them properly! I can't knock the programmes though it brings the kids in.
The adults who only use groin guards and gumshields learn to spar from the first session.Basically we are a fighting club so it plays a very big part in the training. The adults learn techniques that are all geared to fighting, the children probably spar more than most clubs do though we are careful to balance it with kata etc.