Early case assessment
Early case assessment in eDiscovery is the analysis of collected data before full review: volume by custodian, date and file type, search-term hit counts and overlap, domain and communication patterns, and the reduction available from deduplication and threading. Its output is an estimate of how big review will be, what it will cost, and what should be promoted into it.
Also called: ECA · early data assessment · EDA · pre-review analytics · data assessment
Updated September 6, 2026
How does early case assessment work?
After processing and before review, the collection exists as an indexed, searchable set that nobody has read. ECA is the set of questions you ask it.
The standard ones: how much data does each custodian contribute, and does the distribution match what the custodian interviews said; how does volume fall as the date range narrows; how many documents does each proposed search term hit, how many does it hit uniquely, and which terms are hitting a signature block rather than the facts; what proportion of the set is duplicate, near-duplicate or non-inclusive email; which domains and file types dominate.
The answers feed three decisions. What to cull. What to negotiate: a producing party that can show a term adds 40,000 documents and 12 relevant ones has a proportionality argument rather than a complaint. And what review will cost, which is a straightforward multiplication once the promoted document count is known.
ECA is also where problems surface while they are still cheap: a custodian whose mailbox stops six months before the relevant period, a share with 200,000 files nobody mentioned, an exception report full of encrypted archives.
What does early case assessment look like in practice?
Rule 26(b)(1) makes the scope of discovery turn on proportionality, weighing “the importance of the issues at stake in the action, the amount in controversy, the parties’ relative access to relevant information, the parties’ resources, the importance of the discovery in resolving the issues, and whether the burden or expense of the proposed discovery outweighs its likely benefit.” Every one of those factors except the first two is answered with numbers, and ECA is where the numbers come from.
What ECA turns a collection into, using the volume translator’s defaults: a mixed set at 7,000 documents per gigabyte, a 65 percent cull, and 55 documents reviewed per hour:
| Stage | Figure |
|---|---|
| Collected | 130 GB |
| Documents at 7,000 per GB | ~910,000 |
| Promoted after a 65% cull | ~318,500 |
| Review hours at 55 docs/hour | ~5,790 |
The pages-per-gigabyte guide explains where the documents-per-GB figure comes from. Illustrative. Cull rates vary enormously by matter and the documents-per-gigabyte figure is a rule of thumb, not a measurement. The point is that none of these numbers exist before ECA and all of them are needed to answer “what will review cost.” Source for the defaults: src/data/volume.json, used by the volume translator and the cost calculator.
How does early case assessment show up on an eDiscovery invoice?
ECA appears as an ECA or culling fee, priced per gigabyte in, per gigabyte promoted, or both. The Fee Field Guide’s note on it is the one to remember when reading a quote: a vendor paid per hosted gigabyte has little reason to help you shrink the set aggressively.
The fee is small; what it governs is not. Every gigabyte that ECA keeps out of review is a gigabyte that never accrues per-GB monthly hosting for the life of the matter, and every document it keeps out of review is review time that is never billed. That is why ECA is the highest-leverage line on the invoice relative to its size.
What the promoted volume then costs per gigabyte, month after month, is worked through in the cost per GB guide.
Ask: is ECA included or separate; is it charged on data in, data promoted, or both; and does deduplication run before or after the volume that hosting is billed on is measured.
Sources
- Fed. R. Civ. P. 26(b)(1) (proportionality factors, quoted).
- EDRM, model stages: Processing, Review and Analysis.
- The Sedona Conference, Commentary on Achieving Quality in the E-Discovery Process.
- Review-rate and cull defaults:
src/data/volume.json. - Fee structure: the Fee Field Guide dataset.
Related terms
Culling · Technology-assisted review · Processing · Hosting · Deduplication · Proportionality
eDiscovery at one flat monthly rate
$3,250 a month on a 12-month agreement. No per-user fees and no per-GB hosting charges.
Common questions
What is the difference between ECA and culling?
ECA is the measuring; culling is the cutting. ECA tells you how many documents a proposed date range or term list would leave, how much each custodian contributes, and where the duplicates are. Culling applies the decision. In practice they run as one loop (test a term list, see the hit count, adjust, apply) which is why the two are usually billed on the same line.
When should early case assessment happen?
Before the Rule 26(f) conference if the schedule allows, because that is when scope, custodians, date ranges and search methodology are negotiated, and a party arguing proportionality without numbers is arguing from assertion. At minimum it should happen before data is promoted into a hosted review set, since that is the point at which the recurring meter starts.
Is ECA a separate fee?
Often, yes, sometimes per gigabyte in, sometimes per gigabyte promoted to review, sometimes both. That structure deserves attention: it means paying for the reduction and then paying to host what survives it. Ask whether ECA is included, which volume it is charged on, and whether deduplication happens before or after the volume-based fees are calculated.