The following is from the article 'Managing Large Classes' by Instructor Steve Moses
Vetting the students prior to class is important. Consider the nature of the class being taught and the expected level of experience required of the students prior to attending. Students attending an intermediate or advanced handgun class should have successfully completed a basic class first. Students lacking basic skills have no place in a more advanced course and sometimes inadvertently cause a disruption that affects the rest of the class. Instructors should be aware by now that on occasion students will misrepresent their prior experience.
If a student is hopelessly floundering at the beginning of class, they should be removed from the class in accordance with the instructor’s class policy. Instructors who do not have such a policy in place should give some thought to developing one before the next class and consider making the terms of this policy known to the class at time of enrollment. One of the many reasons to have co-instructors and assistant instructors in even small classes is that it may be advantageous to remove struggling students from the main firing line and send them to another part of the range where an instructor can work with them for a while on a personal basis. Many students who struggle at first are often doing quite well by the end of class.
Recently I ejected a student from the line who made me think he was far more capable on the range due to his résumé. He was totally lost when it came to the basic fundamentals I'd covered to ad nauseum in the classroom and as I was the only instructor on the range, I had no other instructor to turn him over to work on the basics. I hated to kick him off but after repeatedly failing basic skills, I could not hold the rest of the class back while working with him. I hope he'll return, but I feel he may not due to the embarrassment factor of being ejected. Time will tell if he returns... but he should, but only after he gets the remedial training I instructed him to get. Only practice, as my mother used to say, will make perfect.