In a traditional classroom environment, there are usually anywhere from twenty to thirty children and one teacher. In some cases, that teacher might have a "teacher's aid" or an assistant teacher. This is where the disadvantage starts- it is simply impossible for one person to give each student the one-on-one attention or instruction that may be required
In a classroom of twenty to thirty children, there are going to be several children with differing learning styles and academic strengths and weaknesses. A teacher and/or teacher's aid is going to be woefully unequipped to handle any and all learning styles or weaknesses. And woe to the teacher who has a couple of students who present themselves as "problem students," a child who is difficult to manage or who disrupts the classroom is also going to take away time that the teacher could be using to help with one-on-one time with his or her students.
Which brings to light the next disadvantage of a traditional classroom. In a traditional classroom environment, it's not uncommon for children to become bored or frustrated. Some children learn better by visual means, others will learn better with auditory means, and still others are going to learn better with a hands-on approach.
It is virtually impossible for a single teacher to accomodate all methods of learning when he or she is responsible for teaching a large number of children. Thus, children who do not fall into the "traditional learning method" category are far more likely to "fall through the cracks," become bored or discouraged, or to display behavior problems in the classroom.
The traditional classroom environment works well for a large number of children, but there are many others who simply have difficulty learning in this environment, have difficulty interacting with peers that are strictly in their age range, or who require more one-on-one attention and time to grasp certain concepts.
The fact that a traditional classroom environment consists of one teacher and a large amount of students, in and of itself, is a big issue. But another issue that should not be ignored is the fact that children are seperated and segregated into classrooms filled with other children only in their own age-range.
In traditional classroom setting, children are taught how to wait their turn, how to treat others with respect and that there are consequences to disobeying the rules, all skills that some parents find difficult to teach in a home environment. As the children age they are monitored less, but there are still very clearly defined rules and the punishment for breaking those rules are consistent and enforced. Inadvertently this teaches the child a decision making process that will serve them well later in life. Is what I am about to do worth the consequences that I will receive for doing it? No one succeeds in this life without taking risks and so the sooner a child learns how to judge the ratio of risk to gain the better equipped they will be to handle important decisions later in life when the consequences can be dire.
Perhaps the most important thing a child can learn in a classroom is how to find their place in a group. Think about your daily interactions as an adult. Whether in the work place or on the road, while shopping or enjoying a night out on the town, how you define yourself within a group of the school day. The desire to protect ones child from these things is very natural but the hard fact is that adult life also has its share of intimidating people and those that would gladly take advantage of you or teach you things you'd rather not learn. Everyone deals with these issues regularly and it is how you deal determines your success or failure at any particular endeavor. Again this skill set, although not specifically in the classroom's curiculum, is an integral part of what is learned there.
Classroom life is not without its risks. Unfortunately intimidation and unsavory characters are also a very real part with these incidences that makes the difference. Allowing your child to encountered these scenarios in the relatively safe environment of a classroom will give them the skills they need to deal with them later in life. Just like learning to chew there are bound to be mistakes made along the way, so watch carefully but allow your children to grow.