How Many are Enough?
Defining “Critical Mass”


By Cheryl DeConde Johnson and Janet DesGeorges

If you’ve been around Deaf Education for any length of time, you’ve probably heard conversations about the importance of and the need for direct communication and authentic peer interactions for students who are deaf/hard of hearing (DHH).  This often leads to a discussion of “critical mass” for DHH kids in school programs.  But what exactly is “critical mass” and how is it achieved?

The term “critical mass” can be defined as the number of students in a classroom, program or school that share common communication modes and characteristics and that is sufficient to support direct interaction opportunities among peers and adults. The attribute of a ‘natural’ critical mass of students is often cited as one of the advantages of schools and special programs for the deaf and hard of hearing. The concept of critical mass however, does not necessarily mean that all of these communication partners are deaf or hard of hearing themselves.

In Colorado, state developed Quality Standards for educating DHH students have articulated different aspects of appropriate services for students.  One such ‘standard’ defines authentic peer interaction. 

“Peer interaction is essential for many aspects of human development, from birth onwards. Children and youth learn a great deal through interactions with others, and interactions with peers appear to be particularly important. The positive effects of having authentic peer interactions are widespread.  Interactions with friends and classmates are essential to social-emotional development, as well as the development of personality. As importantly, being involved in discussions and arguments scaffolds the development of language and cognition. There are many skills that can only be learned during rich, cognitively interesting interactions. Throughout childhood and adolescence, children learn to discuss, negotiate, argue, debate, and create emotional bonds during interactions. These interactions allow children to develop the language skills associated with a particular form of discourse, such as argumentation. There are also cognitive skills required for certain types of discourse, such as seeing a problem from multiple perspectives.

Often, interactions with peers are richer in terms of discussion and argumentation than interactions with adults. These discussions force children to think of alternative perspectives and to learn complex relationships. With peers, children learn what kinds of evidence are legitimate and what debate tactics are acceptable, credible, and productive. Quite literally, peer interactions are food for thought. Not only is interaction with peers essential to language and cognitive development, but interaction with friends seems to provide an even richer context for learning. Children have been found to use better problem-solving skills, write richer and more elaborate text, and use better negotiation and collaboration when working with friends rather than other classmates. Children have more freedom to explore conflicts and resolve disputes with friends than with non-friends or adults.  Despite the essential nature of peer interaction, deaf and hard-of-hearing children often have more difficulty accessing interactions with hearing peers than what is thought. This may be particularly true when a child or youth needs the services of an interpreter to access interactions.” (Colorado Department of Education, 2004; Standard #29, p. 58).

The goal of critical mass is to combine the necessary specialization required to yield full and effective communication and instruction access and quality education programming to DHH students as well as to achieve those services in a cost effective manner. An additional goal of critical mass is to ensure opportunities for the development of self-image and self-identity. Large metropolitan school districts usually have sufficient DHH student numbers to attain critical mass groupings; the largest of these districts can even have specific programs based on communication modality. In smaller districts and in rural areas, school districts may share costs through regional programs. Such programs also reduce duplication of services that are often inadequate. Critical mass numbers for public school programs are relative and affected by such variables as age, student needs, communication approach, geography and family desires. But before discussing each of these areas, let’s look at the IDEA regulations and other national efforts that include critical mass recommendations.

IDEA and other Initiative Considerations

1.  IDEA 20U.SD.C 1414(d)(3)(B)(iv) [IDEA regulations 34CFR300.324(2)(iv)] addresses specific considerations for students who are deaf and hard of hearing, including, “…opportunities for direct communications with peers and professional personnel in the child’s language and communication mode, academic level, and full of range of needs…”    Deaf Child’s Bill of Rights laws enacted in many states address the need and requirement to consider access by DHH students to other peers.

2.  The National Agenda (The National Agenda:  Moving Forward on Achieving Educational Equality for Deaf and Hard of Hearing Students, 2005) recommends that “Deaf and Hard of Hearing children will have as an integral, required part of their educational program, access to a critical mass of age, cognitive, and communication/language peers and teachers and educational staff who are proficient in the individual child’s language and communication mode.  The rationale for this is developed further in the document: “No child should go to school without access to a sufficient number of age and language peers, role models, and educational staff who can communicate directly with them. No children in this nation should go to school wondering whether they will have such access. Teachers, peers, and other adults in the school environment should therefore provide deaf and hard of hearing students with rich and on-going opportunities for direct communication in a manner that supports meaningful participation and interaction, across all components of the educational program.  It is not always possible, of course, to provide a large enough numbers of age and language peers for many deaf and hard of hearing children, especially those who use ASL or signing systems or who live in rural areas. It is because of this fact that the educational system must be sensitive to alternative ways to provide such access.”

3.  NASDSE Deaf Education Service Guidelines
The National Association of State Directors of Special Education (NASDSE)’s educational service guidelines, Meeting the Needs of Students who are Deaf and Hard of Hearing (2006) defines critical mass as “a sufficient number of children functioning in the same language or communication mode, or age group, to ensure that appropriate opportunities for social and intellectual interaction occur. also includes a discussion and recommendations regarding critical mass” (p 85). The concepts of critical mass are addressed in these guidelines through the requirements under IDEA Special Considerations (34CFR300.324(2)(iv). 

Age and Student Need Considerations

Ideally, there would be about three to four students per grade level or about 50 students in a center based school or PS-12th grade program. However, in rural areas some programs might have as few as 12-15 students. When appropriate, multi-age grouping (e.g., 1st-2nd grade, 3rd-4th grade) is an additional way to increase the number of DHH students in a classroom especially when student numbers are low. Depending on how the schools and grades are configured, a PS-12th grade program should have enough students to support at least 2.5 full-time teachers and the support staff that have the specialized expertise to work with those DHH students (.5 preschool, 1.0 elementary, 1.0 secondary). Given the goal of active, authentic participation in the learning process and social environment in school, and attainment of yearly growth targets, general education teachers must have sufficient expertise and commitment to assure a fully accessible environment through providing required accommodations as well as facilitating learning among the students and differentiating instruction when the student needs modification. The deaf education teacher should support the classroom teacher and the students in accommodations and modifications so that they may benefit from their general education learning experience. When students do not have the necessary pre-requisite language/learning skills, general education instruction may not be appropriate in those areas and the deaf education teacher needs to be able to provide the specialized direct instruction necessary for the child to acquire those skills. A DHH program should have sufficient DHH students to support the services of an SLP, an audiologist, a psychologist or counselor, a lead interpreter, and a program coordinator - all of who have expertise with this population (these positions would not necessarily need to be full-time). The number of teachers and support personnel would depend on the numbers and the needs of the students.

Communication Considerations

Complicating the education of higher numbers of students and their individual learning needs is the need to address the variety of communication approaches they use. Is it possible for teachers/interpreters/specialists to individualize for each student’s communication mode (oral, sign, or both) in the same classroom while retaining the integrity of the communication and instruction? Even when this is possible, some professionals recommend to parents of auditory/oral children that their children be educated separately from those who sign. A further complication for the children who sign is the use of English-based sign versus American Sign Language (ASL). For preschool and early elementary programs, it may be determined that separate programs for oral and signing students work best. This decision really depends on the expertise of the deaf education and general education teachers and the other specialists. Deaf students using ASL usually require an environment that incorporates the communication elements of deaf culture including emphasis on visual orientation and direct communication between teachers and students. Another way to address the various communication modes (at least in metropolitan areas) is for individual school feeders (preschool to elementary to middle school to high school programs) or school districts to specialize in a particular communication mode so that students are able to attend the one that matches their communication needs. When multiple school districts are involved, this option requires cooperation across school districts to work out costs, staffing, transportation and other local program management issues.

Geographical Considerations

Students in rural areas add a further complication in that travel time to a regional program may limit the number of students that could attend such a program. Excessive travel time can outweigh the benefits of a center based program for parents who can’t be as involved in the school due to distance or have a child who only has time and energy for school and nothing else due to long commutes. In these situations, other options to bring students together might be explored such as short-term, intensive instruction (i.e., one week every two months with a residential component) or the use of virtual classrooms where students enroll in classes that are taught through a regional center or deaf school. Technology options, such as webcams or videoconferencing, are increasing.  This allows for more students to join in from a variety of locations and to access remote interpreting, classroom captioning, or instructional services.

Family Considerations

For every family who has a child who is deaf or hard of hearing, consideration of school placement for their child should include discussion about the number of students in a program, and the importance for that particular child of meeting the criteria of “critical mass”.  Some of these considerations might include asking the questions:

  • How is my child’s comfort level with self-identity and self-image of him/herself as a DHH person?
  • Is my child actively engaged with peers and in social opportunities?
  • What are our values as parents about our child’s participation with deaf or hard of hearing peers?
  • What is our child’s value about being included with other deaf or hard of hearing students?

One parent made this comment about his experience with a centerbased program, “We thought a center based program better met the needs of our child. There were professionals with years of experience assigned to the building in deaf ed, speech, and audiology, and the general education teachers also had years of experience working with kids like ours. We didn’t have to worry about access to information at assemblies and after school events or sports. My child made friends with both DHH and hearing kids, and it seemed to me that the school tried to create a supportive community through sign language classes and deaf/hh social events for students district wide.”

A supportive and welcoming school community where children are encouraged to learn in a variety of ways with multiple communication partners is essential component to achieving age-appropriate language and academic outcomes.  Critical mass remains an essential consideration for programming development and family considerations for the unique needs of students who are deaf and hard of hearing.  

About the Authors:

Cheryl is self-employed as a consultant in deaf education and educational audiology; she is also the H&V Board of Directors President and a parent of a grown daughter who is usually hard of hearing but sometimes deaf. She can be contacted at

Janet is the executive Director of Colorado Families for Hands & Voices, and the Outreach Director for Hands & Voices National.  ~


Colorado Department of Education (2004), Quality Standards for Educating Students who are Deaf and Hard of Hearing. Denver, CO

The National Agenda:  Moving Forward on Achieving Educational Equality for Deaf and Hard of Hearing Students (2005).

NASDSE (2006), Meeting the Needs of Students who are Deaf or Hard of Hearing: Educational Service Guidelines. Alexandria, VA

Copyright 2014 Hands & Voices   ::   Privacy Policy   ::   Credits