Grettings Georgia!
The negative effects of grouping students based on academic achievement 1) labels those students who are less academically successful, 2) probably see less participation for those who struggle, 3) lowers self-esteem, and 4) doesn't provde that diverse interaction that students need for learning.
Found the following on the internet which wil further help to answer your question.
http://ctl.du.edu/index.php/teaching-resources/du-teaching-resources/213-diversity-in-the-classroom
Diversity in the Classroom
A resource for DU faculty members
Developed by the Center for Multicultural Excellence, University of Denver
One of the critical components of a successful classroom that maximizes the educational benefits to all students is safe space and a welcoming environment. A safe and welcoming classroom is defined as an environment in which all students feel comfortable in expressing themselves and participating fully in the educational process. A hostile and tense classroom can be very unproductive for the educational growth and development of all students.
Both students and faculty have a role and responsibility in creating a safe and welcoming classroom environment. The following are suggested guidelines specifically for faculty and teaching assistants who wish to 1) insure that the broadest range of opinions and ideas on topics are expressed in the classroom in a manner that generates constructive dialogue (rather than destructive discussions) and 2) maintain and protect the dignity of all students and the groups to which they belong. Instructors are not required to adopt the suggested rules. However, those wishing to do so can make them explicit by placing them in the course syllabus and/or reviewing them during the first day of class.
Hope this helps and provides further thought.
Keep up the good work!
Jane Davis
ED106 Facilitator