Disproportionality refers to the overrepresentation or underrepresentation of student groups, relative to their overall enrollment, in educational outcomes such as special education identification, school discipline, and access to gifted, honors, and Advanced Placement (AP) programs. While disproportionality is measured through data, it is much more than a statistical pattern—it is an indicator that educators and school systems should examine how opportunities, decisions, and supports are distributed across students.
The 1997 amendment of IDEA [20 U.S.C. §1418(c), 1998] established a specific policy approach for identifying disproportionality in special education. The language included attention to data collection of disproportionality.
In 2004, the reauthorization of IDEA [20 U.S.C. §1412(a)(22, 24)] further altered the educational policy approach of addressing disproportionality. This led to inclusion of guidance for States to monitor disproportionality, to describe the formula used for identifying disproportionate districts, to require districts found with “significant disproportionality” to set aside up to 15% of IDEA funds for coordinated early intervening services (CEIS) in grades K to 12, and require the school district to publicly report on the revision of policies, practices and procedures.
In 2016, further guidance was provided that identified a common formula for every State Education Agency (SEA) to use for calculating disproportionality - relative risk ratio; SEAs set a reasonable threshold of risk ratio; SEAs set a reasonable threshold of up to three consecutive years of exceeding risk ratio threshold.
As a result of these federal regulations, SEAs are required to provide the provisions to comply:
As a result of SEA meeting federal regulations, individual school districts identified for significant disproportionality are required to conduct the following:

Due to various factors, many school districts did not have in place a current curriculum and/or agreement on
instructional approaches that would be appropriate for a widerange
of learners. As a result, students that persistently could not
attain proficiency on the state exam were promptly considered for
special education services. Additionally, some districts were continuously
changing or adding curriculum, assessment, and instructional
strategies from year to year. Although every school district
contends with such changes, we found in our districts such structural
changes affected struggling learners the most. For example,
practitioners tended to comment that they lacked the ability to
adequately service students at the lowest quartile of performance.
Therefore, instructional staff go through a steep learning curve
regarding a new curriculum and/or assessment, feeling inadequate
to address skill deficiencies with students, even based on the prior
curricula or assessment.

School districts are generally good at ensuring they abide by special education
regulations, including referral timeframes, involvement of practitioners, etc. However, the RCA process also found school districts maintained inconsistent pre-referral information, as well as
different forms for each school building in a district. Again, much of these system inconsistencies were not intentional, but rather reflective of the bifurcation existing in the district between special
education and general education. In many instances, special education directors would describe how they could only suggest to building
administrators adopting one common referral form or insisting
on general education teachers to complete the specifics of the prereferral
strategies.

Special education is viewed as fixing struggling students. In most
school districts, the general and special education staff rarely interact
with each other. The RCA process brought together cross-district
teams that included general and special education teachers, administrators,
content specialists, etc., and more often than not conversation
was interrupted due to a limited understanding among
practitioners regarding what is a disability. General education
teachers tended to express the belief that special education maintains
the “magic fairy dust” that will “fix” the learning capacity and
outcomes of students. Some of this belief may be due to the reality
that prior to the addition of RTI in IDEA 2004, the special education
process was perceived as organized to provide services to students
outside of the normal curve of academic performance. Though RTI
is part of conversation in most school districts, some practitioners
viewed RTI as the new process for “getting student classified” and
not a process for ensuring quality instruction and interventions.

More specifically, school and
district staff perceived at times the cultural practices of the home environment as making low-income and racial/ethnic minority children unable to learn, or contradicting school practices. For
example, in one district, many of the participants rallied around the
concept of “urban behavior” as a driving force of why the Black
students were in special education. In another district, Multi Language Learners were overrepresented in special education with
speech/language impairment because in “Latin culture, they listen
to music loud”; this was hypothesized by an ESL teacher. And yet another district hypothesized the Latino and ELL students are such a distraction in the classroom that they can be better served with
other disability groups. Such perspectives are not solely found in school districts cited for racial/ethnic disproportionality anymore;
in fact, such perspectives can be found in many urban, suburban,
and rural districts as well. Part of the difficulty with such a belief is
its distraction from engaging how teaching matters in learning outcomes.
That is, the belief sessions found practitioners were willing
to cite the family and community (i.e., poverty, limited reading
materials at home) as the reason why poor/low-income and racial/
ethnic minority students were struggling academically, while attributing
the academic performance of proficient students to their teaching practice. So there needs to be a paradigm alignment
regarding the connection between teaching and learning, as well as
an understanding of how to harness the types of knowledge students
demonstrate.

Some of the patterns that emerged in the root cause included schools and at times districts adding behavioral intervention
services to “fix” problem behaviors and limited identification of how climate contributed to behaviors. For example, one school district decided to provide one-on-one behavioral aides for “problem”
kids which resulted in walking into any school and seeing mostly Black boys being shadowed by college-age White or Asian males. Such practices emerge from a focus of addressing an urgent
issue but not identifying the causal factors or function of the factor and the ways in which the environment may contribute to the problem behavior.