One-on-one teaching is more targeted, and the time for a class is limited. The teacher can propose a better plan for you. At the beginning of the training course, it is natural to teach a class at the same time. Of course, it is not as targeted as teaching a person, so it is cheaper.
Extended data:
Violin specifications are mainly divided into three types: adult violin, juvenile violin and children violin.
The body length of "adult (standard) piano" varies from 15 inches, 15.5 inches, 16 inches, 16.5 inches to 17 inches, 18 inches, or even more irregular. Depend on that personal interests of producer and performers. As long as the players' bodies can bear it, most of them will choose a larger viola.
At present, the violin sizes produced at home and abroad are 4/4, 3/4,12, 1/4, 1/8,1/6, 1/32. There are also a few specifications of 7/8, 3/8,110.
The so-called 4/4 and 7/8 are pianos for adults (in fact, boys with normal heads of thirteen or fourteen can use them), and 7/8 is specially for younger adults, especially women. Other pianos under 3/4 size are children's pianos. From 1/32 to 3/4, as children grow up, they will change a size in a year or so.
The sizes of 1/4 and 1/2 are quite different, so there are 3/8 or small 1/2 pianos available.
Data reference:
Baidu encyclopedia-violin