Washington’s Definition of Significant Disproportionality (WAC 392-172A-07040)
Washington defines SIGNIFICANT DISPROPORTIONALITY as a weighted risk
ratio of 4.0 or greater for three consecutive years for any racial/ethnic
group in any of the following areas:
A minimum “n” size is used for both target and comparison groups.
- The identification of children as children with disabilities,
- The identification of children with a particular disability,
- The placement of children in particular educational settings (LRE Tables 2, 3, 28, or 29), or
- The incidence, duration, and type of disciplinary
actions, including suspensions and expulsions.
The weighted risk ratio is a measure of the risk that a student from a
specific racial/ethnic group will be served in a specific disability
category compared to the risk of all other students being served in that
category. For example, a weighted risk ratio of 1.00 means that students
from that group are as likely to be served in the category as all other
students. A weighted risk ratio greater than 1.00 indicates the degree to
which students in the racial/ethnic group are over-represented. Therefore, a
weighted risk ratio of 4.17 in the EBD-Black category means that Black
students in the district are 4.17 times more likely to be identified in the
EBD category than all other students. A weighted risk ratio less than 1.00
indicates the degree to which students from the racial/ethnic group are
under-represented. For example, a weighted risk ratio of 0.50 in the
MR-Black category means that Black students in the district are half as
likely to be identified in the MR disability category as all other students.
Weighted Risk Ratio (WRR)
*Note: The results of the calculations will be verified using multiple methods.
||>0.5 to <0.67
||0.67 to 1.5
||>1.5 to <2.0
||≥2.0 to <3.0
||≥3.0 to <4.0
(3 consecutive years)
|Disproportionate Under- representation
||At Risk for Disproportionate Under-
||At Risk for
Disproportionate Over- representation
||At Risk for Significant
- Summary Planning Worksheet
– Districts that are found to have significant
disproportionality must complete this summary of the
district’s policy, procedure, and practice review/revision
process and submit it to OSPI (via iGrants Form Package 442) no
later than April 30 of the year in which they are found to have significant disproportionality. Districts not identified as having significant disproportionality may use this worksheet as an optional self-review tool.
- Additional resources related to disproportionality
(Indicators 4, 9, and 10) can be found on OSPI’s
Disproportionality Technical Assistance
- Individual district data related to indicators 4, 9, and 10
can be found on the
(Data included in the FFY 2009 APR).
Special Education Accountability Q&A – revised August
2010 – This question and answer document addresses the
primary federal and Washington state requirements for
accountability under IDEA, including district
determinations, correction of non-compliance, the program
review process, and significant disproportionality.