Calculator Inputs
Example Data Table
| Area | Group A | Group B | Use Case |
|---|---|---|---|
| North District | 120 | 80 | School, housing, or workplace study |
| South District | 45 | 155 | Community distribution review |
| East District | 90 | 110 | Balanced area comparison |
Formula Used
Dissimilarity Index: D = 0.5 × Σ | ai / A - bi / B |
Here, ai is the first group count in one area. A is the first group total. bi is the second group count in one area. B is the second group total.
Isolation: Σ (ai / A) × (ai / ti)
Exposure: Σ (ai / A) × (bi / ti)
Theil Entropy: H = Σ ti × (E - Ei) / (T × E)
The combined score averages dissimilarity and entropy. A higher score suggests stronger separation between the two groups.
How to Use This Calculator
- Enter a name for each comparison group.
- Paste area data using one row per area.
- Keep three columns: area, first group, second group.
- Adjust threshold limits if your project needs custom categories.
- Choose decimal places for cleaner reporting.
- Press the calculate button.
- Review the result above the form.
- Download the CSV or PDF summary when needed.
What Is Segregation?
A Practical Meaning
Segregation means separation between groups across places, systems, or categories. It can appear in housing, schools, jobs, services, or public resources. The idea is simple. If two groups are spread evenly across every area, segregation is low. If one group is concentrated in some areas, while another group is concentrated elsewhere, segregation is higher.
Why Measurement Matters
A calculator helps turn raw counts into readable indexes. This is useful for reports, lessons, planning work, and basic research. Counts alone can hide patterns. Two cities may have the same population totals, yet show very different area patterns. Indexes make that difference easier to compare.
Core Indexes
The dissimilarity index estimates how unevenly two groups are distributed. A score near zero means the groups follow similar area patterns. A score near one hundred means the groups are strongly separated. The isolation index shows how often a typical member of one group shares an area with the same group. The exposure index shows contact with the other group.
Entropy View
The entropy index looks at diversity inside each area. It compares each local mix with the overall mix. If every area matches the whole population, entropy segregation is low. If each area has a very different mix, entropy segregation rises. This gives a broader view than one simple share.
Reading the Result
Use the combined score as a guide, not a legal finding. Low scores suggest broad mixing. Moderate scores suggest uneven distribution. High scores suggest strong separation. Always review the area table too. One large area can influence the final score. Small areas can also create sharp local patterns.
Good Data Practice
Use clear group definitions. Keep area boundaries consistent. Avoid mixing years or sources. Check missing values before calculating. For public work, explain the data source and limits. Segregation numbers are powerful, but context gives them meaning.
FAQs
What does this segregation calculator measure?
It measures how two groups are distributed across areas. It uses dissimilarity, exposure, isolation, and entropy indexes to summarize separation patterns.
Can I use this for schools or housing?
Yes. You can use it for any two-group area comparison, including schools, housing zones, offices, branches, neighborhoods, or service regions.
What is a high dissimilarity score?
A high score means the two groups are unevenly spread. Many studies treat higher values as stronger separation, but context should guide interpretation.
What does isolation mean here?
Isolation estimates how much a typical member of one group shares an area with members of the same group.
What does exposure mean here?
Exposure estimates how much a typical member of one group shares an area with members of the other group.
Should zero rows be included?
Usually no. Empty areas can distort interpretation. Use the checkbox to exclude rows where both group counts are zero.
Can I change the level thresholds?
Yes. The low and moderate threshold fields let you adjust categories for your own reporting method or teaching standard.
Is this a legal segregation test?
No. It is an educational and analytical tool. Legal, policy, or compliance decisions need expert review and proper data validation.