Classrooms that are overflowing with students do not breed an environment for individualized attention, which is important for student achievement. As teachers attempt to educate the masses, they have little time for providing one-to-one assistance. This means that only some of the students will receive the help or clarification they need, while others will have to seek help outside the classroom. On the other hand, a small-sized class allows teachers to provide individualized attention, so that students end up feeling more comfortable with the lessons and understand what they need to know for homework.
The larger the class size, the noisier the classroom. Noise pollution is a serious issue that plagues schools with overly populated classes. Gary Evans, a professor of design and environmental analysis and human development at Cornell University, participated in a study in 1996 that found a link between noise pollution and student reading delays. Not only did the study show that noise pollution was distracting to students, but it also demonstrated that students learned how to tune out all the environmental noises -- including the teachers. Consequently, class size has an impact on how well students are able to listen to their teachers and hear what is being taught, which, in turn, affects their level of academic achievement.
A class with too many students can cause a teacher to spend a chunk of time managing students' behavior, thereby taking time away from teaching. When students are piled together into one classroom, they can become rowdy, rambunctious and sometimes unruly, depending on the individuals in the class. The teacher is then forced to mitigate the behaviors to keep the classroom quiet and peaceful, which can interrupt the student learning process and jeopardize student achievement. In smaller classes, educators do not spend as much time managing behavior and are able to provide a more comprehensive lesson plan that benefits the students.
If students are unhappy with the large class size, it's possible for them to develop a distaste for school and academics. This distaste can turn into a lack of motivation to try to do well, which limits student achievement. Some students may begin to not care about doing homework, passing tests and moving up to the next grade. In a classroom environment that's not crowded, teachers can keep students stimulated and interested in the educational process, so that they are less likely to be unhappy and more likely to have a positive learning experience.