| name | education-data-source-crdc |
| description | CRDC — biennial OCR survey of all U.S. public schools (2011-2021). Discipline, course access, harassment, restraint/seclusion by race/sex/disability/EL. Use for civil rights and equity analysis. 2020-21 COVID-impacted; 2011-14 sampled, not universe. |
| metadata | {"audience":"any-agent","domain":"data-source","skill-authored":"2026-02-09","skill-last-updated":"2026-02-09"} |
CRDC Data Source Reference
Civil Rights Data Collection (CRDC) — mandatory biennial OCR survey of all U.S. public schools measuring educational opportunity and civil rights compliance (2011-2021). Use when analyzing school discipline disparities by race/disability, course access equity, harassment, restraint/seclusion, or chronic absenteeism. Data disaggregated by race, sex, disability, and English learner status. Note: 2020-21 is COVID-impacted and not directly comparable to other years; 2011-14 are sampled, not universe.
The Civil Rights Data Collection is a mandatory biennial survey of all U.S. public schools measuring educational opportunity and civil rights compliance. It is the only national source for school-level discipline disparities, course access equity, harassment, and restraint/seclusion data disaggregated by race, sex, disability, and English learner status.
CRITICAL: Value Encoding
The Education Data Portal uses integer codes, not the string codes shown in OCR documentation. Always filter using integers.
| Variable | String Code (Raw) | Portal Integer |
|---|
| Race: White | WH | 1 |
| Race: Black | BL | 2 |
| Race: Hispanic | HI | 3 |
| Sex: Male | M | 1 |
| Sex: Female | F | 2 |
See ./references/variable-definitions.md for complete encoding tables.
What is CRDC?
The Civil Rights Data Collection is a mandatory biennial survey of all public schools and districts that measures educational opportunity and civil rights compliance:
- Collector: U.S. Department of Education, Office for Civil Rights (OCR)
- Purpose: Enforce civil rights laws, identify discrimination, monitor equity
- Coverage: All public LEAs and schools receiving federal financial assistance
- Frequency: Biennial (every 2 school years)
- Disaggregation: Race/ethnicity, sex, disability status, English learner status
- History: Collected since 1968 (as Elementary and Secondary School Civil Rights Survey)
- Available years: 2011, 2013, 2015, 2017, 2020, 2021 (biennial — no data for even-numbered school years)
- Available through: Education Data Portal mirrors
Reference File Structure
| File | Purpose | When to Read |
|---|
civil-rights-context.md | Legal framework (Title VI, IX, Section 504, IDEA) | Understanding why data is collected |
data-elements.md | All data categories and what's collected | Planning analysis, identifying variables |
collection-methodology.md | Sampling, universe, timeline, reporting | Understanding coverage limitations |
variable-definitions.md | Key variables, codes, disaggregation categories | Coding data, interpreting values |
data-quality.md | Known issues, suppression, state variations | Addressing limitations in analysis |
historical-changes.md | Evolution across collection years | Time series analysis, year comparison |
Decision Trees
What CRDC data do I need?
Research topic?
├─ School discipline
│ ├─ Suspensions (ISS/OSS) → ./references/data-elements.md#discipline
│ ├─ Expulsions → ./references/data-elements.md#discipline
│ ├─ Referrals to law enforcement → ./references/data-elements.md#discipline
│ ├─ School-related arrests → ./references/data-elements.md#discipline
│ └─ Preschool suspensions → ./references/data-elements.md#discipline
├─ Restraint and seclusion
│ └─ Physical restraint, mechanical, seclusion → ./references/data-elements.md#restraint-seclusion
├─ Harassment and bullying
│ ├─ Allegations by type → ./references/data-elements.md#harassment
│ └─ Disciplined for harassment → ./references/data-elements.md#harassment
├─ Course access and enrollment
│ ├─ AP/IB courses → ./references/data-elements.md#advanced-courses
│ ├─ Gifted/talented → ./references/data-elements.md#gifted-talented
│ ├─ Math/science courses → ./references/data-elements.md#course-access
│ └─ Computer science → ./references/data-elements.md#course-access
├─ Chronic absenteeism
│ └─ Students missing 15+ days → ./references/data-elements.md#chronic-absenteeism
├─ Special populations
│ ├─ Students with disabilities (IDEA) → ./references/data-elements.md#students-with-disabilities
│ ├─ English learners → ./references/data-elements.md#english-learners
│ └─ Preschool enrollment → ./references/data-elements.md#preschool
├─ School staffing
│ ├─ Teacher experience/certification → ./references/data-elements.md#staffing
│ └─ Counselors, nurses, etc. → ./references/data-elements.md#staffing
└─ School safety
└─ Offenses, violence, weapons → ./references/data-elements.md#school-offenses
Understanding the legal context?
Civil rights law question?
├─ Race/ethnicity discrimination → ./references/civil-rights-context.md#title-vi
├─ Sex/gender discrimination → ./references/civil-rights-context.md#title-ix
├─ Disability discrimination → ./references/civil-rights-context.md#section-504
├─ Special education services → ./references/civil-rights-context.md#idea
├─ Age discrimination → ./references/civil-rights-context.md#age-discrimination-act
└─ OCR enforcement process → ./references/civil-rights-context.md#ocr-enforcement
Data quality concerns?
Data quality issue?
├─ Missing or suppressed data → ./references/data-quality.md#suppression
├─ Definition inconsistencies → ./references/data-quality.md#definition-variation
├─ Year-to-year comparability → ./references/historical-changes.md
├─ COVID-19 impact (2020-21) → ./references/data-quality.md#covid-impact
├─ Underreporting concerns → ./references/data-quality.md#underreporting
└─ State-level variations → ./references/data-quality.md#state-variations
Quick Reference: CRDC Data Categories
Collection Years
| School Year | Collection | Coverage | Key Notes |
|---|
| 2011-12 | Sample | ~7,000 districts | First modern CRDC; sampled |
| 2013-14 | Expanded | ~16,000 districts | Larger sample |
| 2015-16 | Near-universe | ~96,000 schools | First near-complete |
| 2017-18 | Universe | ~96,000 schools | Full universe collection |
| 2020-21 | Universe | ~97,500 schools | COVID-impacted year |
| 2021-22 | Universe | ~98,000 schools | Post-pandemic baseline |
| 2023-24 | Universe | In progress | Current collection |
Critical: CRDC is biennial - no data for odd years (2012, 2014, 2016, 2018, 2019).
Data Categories
| Category | Description | Disaggregation |
|---|
| Enrollment | Student counts by grade level | Race, sex, disability, LEP |
| Discipline | Suspensions, expulsions, arrests | Race, sex, disability, LEP |
| Restraint/Seclusion | Physical/mechanical restraint, seclusion | Race, sex, disability |
| Harassment | Allegations and discipline by type | Race, sex, disability |
| Course Access | AP, IB, math, science, CS offerings | School-level, enrollment by race/sex |
| Chronic Absenteeism | 15+ days missed | Race, sex, disability, LEP |
| Staffing | Teachers, counselors, nurses, etc. | FTE counts, qualifications |
| Offenses | Violence, weapons, drugs at school | Type of offense |
| Retention | Students retained in grade | Race, sex, disability |
Key Identifiers
| ID | Format | Level | Example | Notes |
|---|
crdc_id | 12-digit string | School | 010000201705 | Primary CRDC identifier; always present |
ncessch | 12-digit string | School | 010000201705 | NCES school ID, joins to CCD; may be null for some entries |
leaid | 7-digit string | District | 0100002 | NCES district ID, joins to CCD; always present |
Note: The OCR-internal combokey (e.g., AL-0010-00002) does NOT appear as a column in Portal data. Use crdc_id or ncessch for school-level identification.
WARNING: String Type Override Required. When reading CRDC data from CSV, ncessch, leaid, and crdc_id must be read as String (pl.Utf8) via schema_overrides. Polars infers these as Int64, silently destroying leading zeros for ~19% of rows (FIPS 01-09 states: AL, AK, AZ, AR, CA, CO, CT). Parquet files preserve types automatically.
Race/Ethnicity (Portal Integer Codes)
| Code | Category |
|---|
1 | White |
2 | Black or African American |
3 | Hispanic/Latino of any race |
4 | Asian |
5 | American Indian or Alaska Native |
6 | Native Hawaiian or Other Pacific Islander |
7 | Two or more races |
99 | Total |
Empirically observed values: Codes 1-7 and 99 appear in CRDC data. Additional codes (8 Nonresident alien, 9 Unknown, 20 Other) are defined in the codebook but are not observed in practice for K-12 CRDC datasets. See variable-definitions.md for the full codebook listing.
Sex (Portal Integer Codes)
| Code | Category |
|---|
1 | Male |
2 | Female |
3 | Non-binary/other (newer collections; rows exist but mostly contain -1 or -2 values) |
99 | Total |
Disability Status (Portal Integer Codes)
| Code | Category |
|---|
0 | Students without disabilities |
1 | Students with disabilities (served under IDEA) |
2 | Students with Section 504 only |
3 | Students not served under IDEA (includes 504-only and non-disabled) |
4 | Students with disabilities (combined: IDEA + Section 504) |
99 | Total |
Note: Not all disability codes appear in every dataset. Enrollment data typically has [1, 2, 99]; discipline data has [0, 1, 2, 4, 99]. Verify codes against the live codebook for your specific dataset.
English Learner Status (Portal Integer Codes)
| Code | Category |
|---|
1 | English learner (EL/LEP) |
99 | All students |
Missing Data Codes
| Code | Meaning | When Used |
|---|
-1 | Missing | Data not reported by school/district |
-2 | Not applicable | Item doesn't apply to this entity |
-3 | Suppressed | Data suppressed for privacy (small cell sizes) |
-9 | Skip pattern | Question not asked in this collection year (rare; check codebook) |
null | Not available | Value absent from dataset (e.g., ncessch is null for some schools) |
Verify these codes against the live codebook for your specific dataset. Use get_codebook_url() from fetch-patterns.md.
Data Access
Datasets for CRDC are available via the Education Data Portal mirror system. See datasets-reference.md for canonical paths, mirrors.yaml for mirror configuration, and fetch-patterns.md for fetch code patterns including fetch_from_mirrors() and fetch_yearly_from_mirrors().
Key datasets (6 of 22 total):
| Dataset | Path | Type | Codebook |
|---|
| Discipline | crdc/schools_crdc_discipline_k12_{year} | Yearly | crdc/codebook_schools_crdc_discipline |
| AP/IB Enrollment | crdc/schools_crdc_apib_enroll | Single | crdc/codebook_schools_crdc_ap-ib-enrollment |
| Enrollment | crdc/schools_crdc_enrollment_k12_{year} | Yearly | crdc/codebook_schools_crdc_enrollment |
| Chronic Absenteeism | crdc/schools_crdc_chronic_absenteeism_{year} | Yearly | crdc/codebook_schools_crdc_chronic-absenteeism |
| Harassment/Bullying | crdc/schools_crdc_harass_bully_students_{year} | Yearly | crdc/codebook_schools_crdc_harrassment-bullying-students |
| Restraint/Seclusion | crdc/schools_crdc_restraint_seclusion_students_{year} | Yearly | crdc/codebook_schools_crdc_restraint-seclusion-students |
22 CRDC datasets exist total (6 yearly, 16 single-file). See datasets-reference.md for the complete list with all paths and codebook references.
CRDC naming note: Some data file paths use concatenated names (e.g., disciplineinstances, mathandscience) while their codebook counterparts use underscored names (e.g., discipline_instances, math_and_science). Always use the exact paths from datasets-reference.md.
Codebooks are .xls files co-located with data in all mirrors. Use get_codebook_url() from fetch-patterns.md to construct download URLs:
from fetch_patterns import get_codebook_url
url = get_codebook_url("crdc/codebook_schools_crdc_discipline")
Truth Hierarchy: When interpreting variable values, apply this priority:
- Actual data file (what you observe in the parquet/CSV) -- this IS the truth
- Live codebook (.xls in mirror) -- authoritative documentation, may lag
- This skill documentation -- convenient summary, may drift from codebook
If this documentation contradicts the codebook, trust the codebook. If the codebook contradicts observed data, trust the data and investigate.
Filtering
import polars as pl
df = df.filter(
(pl.col("fips") == 6) &
(pl.col("race") < 99)
)
df = df.filter(
(pl.col("race") == 2) &
(pl.col("sex") == 99) &
(pl.col("disability") == 99)
)
Common Pitfalls
| Pitfall | Issue | Solution |
|---|
| Using string codes | Portal uses integers, not strings | race == 2 not race == "BL" |
| Raw counts | Different enrollment sizes | Use rates per 100/1000 students |
| Missing years | Assuming annual data | Remember biennial schedule |
| COVID year | 2020-21 not comparable | Flag or exclude from trends |
| Suppression | Small cell suppression | Check suppression rates first |
| Sample years | Early years sampled | Use 2015+ for national estimates |
| Definition drift | Variables change over time | Check codebooks for each year |
| Forgetting code 99 | Including totals in calculations | Filter race < 99 for disaggregated analysis |
| CSV type inference | Polars infers ncessch/leaid/crdc_id as Int64 | Use schema_overrides={"ncessch": pl.Utf8, "leaid": pl.Utf8, "crdc_id": pl.Utf8} |
Equity Analysis Framework
CRDC data is designed for civil rights analysis. Key analytical approaches:
Disparity Ratios
import polars as pl
def discipline_disparity(df, discipline_var, group_a, group_b):
"""
Calculate risk ratio between two groups.
Value > 1 indicates group_a has higher rate.
Args:
df: DataFrame with CRDC data
discipline_var: Column with discipline counts
group_a: Integer race code (e.g., 2 for Black)
group_b: Integer race code (e.g., 1 for White)
Example:
# Black vs White OSS disparity
disparity = discipline_disparity(df, 'students_susp_out_sch_single', 2, 1)
"""
df_a = df.filter(pl.col('race') == group_a)
df_b = df.filter(pl.col('race') == group_b)
rate_a = df_a.select(pl.col(discipline_var).sum()).item() / \
df_a.select(pl.col('enrollment_crdc').sum()).item()
rate_b = df_b.select(pl.col(discipline_var).sum()).item() / \
df_b.select(pl.col('enrollment_crdc').sum()).item()
return rate_a / rate_b
Composition vs. Representation
- Composition: What share of suspended students are Black?
- Representation: Are Black students suspended at higher rates than enrollment share?
Risk Ratios
- Compare discipline/outcome rates across groups
- Adjust for school-level factors when appropriate
Related Data Sources
| Source | Relationship | When to Use |
|---|
education-data-source-ccd | School/district characteristics | Linking CRDC to school demographics, locale, Title I status (join on ncessch or leaid) |
education-data-source-edfacts | Assessment outcomes | Comparing discipline patterns to academic outcomes |
education-data-explorer | Parent discovery skill | Finding available CRDC endpoints and variables |
education-data-query | Data fetching | Downloading CRDC parquet/CSV files from mirrors |
education-data-context | General interpretation | Education data interpretation and citation generation |
Topic Index
| Topic | Reference File |
|---|
| Title VI (race) | ./references/civil-rights-context.md |
| Title IX (sex) | ./references/civil-rights-context.md |
| Section 504 (disability) | ./references/civil-rights-context.md |
| IDEA | ./references/civil-rights-context.md |
| OCR enforcement | ./references/civil-rights-context.md |
| Discipline data | ./references/data-elements.md |
| Restraint/seclusion | ./references/data-elements.md |
| Harassment | ./references/data-elements.md |
| Course access | ./references/data-elements.md |
| AP/IB/Gifted | ./references/data-elements.md |
| Chronic absenteeism | ./references/data-elements.md |
| Staffing | ./references/data-elements.md |
| Preschool | ./references/data-elements.md |
| Sampling approach | ./references/collection-methodology.md |
| Collection timeline | ./references/collection-methodology.md |
| Variable codes | ./references/variable-definitions.md |
| Suppression rules | ./references/data-quality.md |
| COVID impact | ./references/data-quality.md |
| Year changes | ./references/historical-changes.md |
