Elusion Random Sample Test Ordered Under Rule 26(g) in a Keyword Search Based Discovery Plan

There is a new case out of Chicago that advances the jurisprudence of my sub-specialty, Legal Search. City of Rockford v. Mallinckrodt ARD Inc., 2018 WL 3766673, Case 3:17-cv-50107 (N.D. Ill., Aug. 7, 2018). This discovery order was written by U.S. Magistrate Judge Iain Johnston who entitled it: “Order Establishing Production Protocol for Electronically Stored Information.” The opinion is both advanced and humorous, destined to be an oft-cited favorite for many. Thank you Judge Johnston.

In City of Rockford an Elusion random sample quality assurance test was required as part of the parties discovery plan to meet the reasonable efforts requirements of Rule 26(g). The random sample procedure proposed was found to impose only a proportional, reasonable burden under Rule 26(b)(1). What makes this holding particularly interesting is that an Elusion test is commonly employed in predictive coding projects, but here the parties had agreed to a keyword search based discovery plan. Also see: Tara Emory, PMP, Court Holds that Math Matters for eDiscovery Keyword Search,  Urges Lawyers to Abandon their Fear of Technology (Driven, (August 16, 2018) (“party using keywords was required to test the search effectiveness by sampling the set of documents that did not contain the keywords.”)

The Known Unknowns and Unknown Unknowns

Judge Johnston begins his order in City of Rockford with a famous quote by Donald Rumseld, a two-time Secretary of Defense.

“[A]s we know there are known knowns; there are things we know we know. We also know there are known unknowns; that is to say we know there are some things we do not know. . .”
Donald Rumseld

For those not familiar with this famous Known Knowns quip, here is a video of the original:

Here the knowledge logic is spelled out in a chart, since I know we all love that sort of thing. Deconstructing Rumsfeld: Knowledge and Ignorance in the Age of Innovation (Inovo 5/114).

Anybody who does complex investigations is familiar with this problem. Indeed, you can argue this insight is fundamental to all of science and experimental method. Logan, David C. (March 1, 2009). “Known knowns, known unknowns, unknown unknowns and the propagation of scientific enquiry”, Journal of Experimental Botany 60 (3). pp. 712–4. [I have always wanted to quote a botany journal.]

How do you deal with the known unknowns and the unknown unknowns, the information that we don’t even know that we don’t know about? The deep, hidden information that is both obtuse and rare. Information that is hard to retrieve and harder still to prove does not exist at all. Are you chasing something that might not exist? Something unknown because nonexistent? Such as an overlooked Highly Relevant document? (The stuff of nightmares!) Are you searching for nothing? Zero? If you find it, what does that mean? What can be known and what can never be known? Scientists, investigators and the Secretary of Defense alike all have to ponder these questions and all want to use the best tools and best people possible to do so. See: Deconstructing Rumsfeld: Knowledge and Ignorance in the Age of Innovation (Inovo 5/114).

Seeking Knowledge of the Unknown Elusion Error Rate

These big questions, though interesting, are not why Judge Johnston started his opinion with the Rumseld quote. Instead, he used the quote to emphasize that new e-discovery methods, namely random sampling and statistical analysis, can empower lawyers to know what they never did before. A technical way to know the known unknowns. For instance, a way to know the number of relevant documents that will be missed and not produced: the documents that elude retrieval.

As the opinion and this blog will explain, you can do that, know that, by using an Elusion random sample of the null-set. The statistical analysis of the sample transforms the unknown quantity to a known (subject to statistical probabilities and range). It allows lawyers to know, at least within a range, the number of relevant documents that have not been found. This is a very useful quality assurance method that relies on objective measurements to demonstrate success of your project, which here is information retrieval. This and other random sampling methods allow for the calculation of Recall, meaning the percent of total relevant documents found. This is another math-based, quality assurance tool in the field of information retrieval.

One of the main points Judge Johnston makes in his order is that lawyers should embrace this kind of technical knowledge, not shy away from it. As Tara Emory said in her article, Court Holds that Math Matters for eDiscovery Keyword Search:

A producing party must determine that its search process was reasonable. In many cases, the best way to do this is with objective metrics. Producing parties often put significant effort into brainstorming keywords, interviewing witnesses to determine additional terms, negotiating terms with the other party, and testing the documents containing their keywords to eliminate false positives. However, these efforts often still fail to identify documents if important keywords were missed, and sampling the null set is a simple, reasonable way to test whether additional keywords are needed. …

It is important to overcome the fear of technology and its related jargon, which can help counsel demonstrate the reasonableness of search and production process. As Judge Johnston explains, sampling the null set is a process to determine “the known unknown,” which “is the number of the documents that will be missed and not produced.” Judge Johnson disagreed with the defendants’ argument “that searching the null set would be costly and burdensome.” The Order requires Defendants to sample their null set at a 95% +/-2% margin of error (which, even for a very large set of documents, would be about 2,400 documents to review).[4] By taking these measures—either with TAR or with search terms, counsel can more appropriately represent that they have undertaken a “reasonable inquiry” for relevant information within the meaning of FRCP 26(g)(1).

Small Discovery Dispute in an Ocean of Cooperation

Judge Johnston was not asked to solve the deep mysteries of knowing and not knowing in City of Rockford. The parties came to him instead with an interesting, esoteric discovery dispute. They had agreed on a great number of things, for which the court profusely congratulated them.

The attorneys are commended for this cooperation, and their clients should appreciate their efforts in this regard. The Court certainly does. The litigation so far is a solid example that zealous advocacy is not necessarily incompatible with cooperation. The current issue before the Court is an example of that advocacy and cooperation. The parties have worked to develop a protocol for the production of ESI in this case, but have now reached an impasse as to one aspect of the protocol.

The parties disagreed on whether to include a document review quality assurance test in the protocol. The Plaintiffs wanted one and the Defendants did not. Too burdensome they said.

To be specific, the Plaintiffs wanted a test where the efficacy of any parties production would be tested by use of an Elusion type of Random Sample of the documents not produced. The Defendants opposed any specific test. Instead, they wanted the discovery protocol to say that if the receiving party had concerns about the adequacy of the producing party’s efforts, then they would have a conference to address the concerns.

Judge Johnston ruled for the plaintiff in this dispute and ordered a  random elusion sample to be taken after the defendant stopped work and completed production. In this case it was a good decision, but should not be routinely required in all matters.

The Stop Decision and Elusion Sample

One of the fundamental problems in any investigation is to know when you should stop the investigation because it is no longer worth the effort to carry on. When has a reasonable effort been completed? Ideally this happens after all of the important documents have already been found. At that point you should stop the effort and move on to a new project. Alternatively, perhaps you should keep on going and look for more? Should you stop or not?

In Legal Search we all this the “Stop Decision.” Should you conclude the investigation or continue further AI training rounds and other search. As explained in the e-Discovery Team TAR Course:

The all important stop decision is a legal, statistical decision requiring a holistic approach, including metrics, sampling and over-all project assessment.You decide to stop the review after weighing a multitude of considerations. Then you test your decision with a random sample in Step Seven.

See: TAR Course: 15th Class – Step Seven – ZEN Quality Assurance Tests.

If you want to go deeper into this, then listen in on this TAR Course lecture on the Stop decision.

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Once a decision is made to Stop, then a well managed document review project will use different tools and metrics to verify that the Stop decision was correct. Judge Johnston in City of Rockford used one of my favorite tools, the Elusion random sample that I teach in the e-Discovery Team TAR Course. This type of random sample is called an Elusion sample.

Judge Johnston ordered an Elusion type random sample of the null set in City of Rockford. The sample would determine the range of relevant documents that likely eluded you. These are called False Negatives. Documents presumed Irrelevant and withheld that were in fact Relevant and should have been produced. The Elusion sample is designed to give you information on the total number of Relevant documents that were likely missed, unretrieved, unreviewed and not produced or logged. The fewer the number of False Negatives the better the Recall of True Positives. The goal is to find, to retrieve, all of the Relevant ESI in the collection.

Another way to say the same thing is to say that the goal is Zero False Negatives. You do not miss a single relevant file. Every file designated Irrelevant is in fact not relevant. They are all True Negatives. That would be Total Recall: “the Truth, the Whole Truth …” But that is very rare and some error, some False Negatives, are expected in every large information retrieval project. Some relevant documents will almost always be missed, so the goal is to make the False Negatives inconsequential and keep the Elusion rate low.

Here is how Judge Iain Johnston explained the random sample:

Plaintiffs propose a random sample of the null set. (The “null set” is the set of documents that are not returned as responsive by a search process, or that are identified as not relevant by a review process. See Maura R. Grossman & Gordon v. Cormack, The Grossman-Cormack Glossary of Technology-Assisted Review, 7 Fed. Cts. L. Rev. 1, 25 (2013). The null set can be used to determine “elusion,” which is the fraction of documents identified as non-relevant by a search or review effort that are, in fact, relevant. Elusion is estimated by taking a random sample of the null set and determining how many or what portion of documents are actually relevant. Id. at 15.) FN 2

Judge Johnston’s Footnote Two is interesting for two reasons. One, it attempts to calm lawyers who freak out when hearing anything having to do with math or statistics, much less information science and technology. Two, it does so with a reference to Fizbo the clown.

The Court pauses here for a moment to calm down litigators less familiar with ESI. (You know who you are.) In life, there are many things to be scared of, including, but not limited to, spiders, sharks, and clowns – definitely clowns , even Fizbo. ESI is not something to be scared of. The same is true for all the terms and jargon related to ESI. … So don’t freak out.

Accept on Zero Error for Hot Documents

Although this is not addressed in the court order, in my personal view, no False Negatives, iw – overlooked  documents – are acceptable when it comes to Highly Relevant documents. If even one document like that is found in the sample, one Highly Relevant Document, then the Elusion test has failed in my view. You must conclude that the Stop decision was wrong and training and document review must recommence. That is called an Accept on Zero Error test for any hot documents found. Of course my personal views on best practice here assume the use of AI ranking, and the parties in City of Rockford only used keyword search. Apparently they were not doing machine training at all.

The odds of finding False Negatives, assuming that only a few exist (very low prevalence) and the database is large, are very unlikely in a modest sized random sample. With very low prevalence of relevant ESI the test can be of limited effectiveness. That is an inherent problem with low prevalence and random sampling. That is why statistics have only limited effectiveness and should be considered part of a total quality control program. See Zero Error Numerics: ZEN. Math matters, but so too does good project management and communications.

The inherent problem with random sampling is that the only way to reduce the error interval is to increase the size of the sample. For instance, to decrease the margin of error to only 2% either way, a total error of 4%, a random sample size of around 2,400 documents is needed. Even though that narrows the error rate to 4%, there is still another error factor of the Confidence Level, here at 95%. Still, it is not worth the effort to review even more sample documents to reduce that to a 99% Level.

Random sampling has limitations in low prevalence datasets, which is typical in e-discovery, but still sampling can be very useful. Due to this rarity issue, and the care that producing parties always take to attain high Recall, any documents found in an Elusion random sample should be carefully studied to see if they are of any significance. We look very carefully at any new documents found that are of a kind not seen before. That is unusual. Typically  any relevant documents found by random sample of the elusion set are of a type that have been seen before, often many, many times before. These “same old, same old” type of documents are of no importance to the investigation at this point.

Most email related datasets are filled with duplicative, low value data. It is not exactly irrelevant noise, but it is not a helpful signal either. We do not care if we  get all of that kind of merely relevant data. What we really want are the Hot Docs, the high value Highly Relevant ESI, or at least Relevant and of a kind not seen before. That is why the Accept On Zero Error test is so important for Highly Relevant documents.

The Elusion Test in City of Rockford 

In City of Rockford Judge Johnston considered a discovery stipulation where the parties had agreed to use a typical keyword search protocol, but disagreed on a quality assurance protocol. Judge Johnston held:

With key word searching (as with any retrieval process), without doubt, relevant documents will be produced, and without doubt, some relevant documents will be missed and not produced. That is a known known. The known unknown is the number of the documents that will be missed and not produced.

Back to the False Negatives again, the known unknown. Judge Johnston continues his analysis:

But there is a process by which to determine that answer, thereby making the known unknown a known known. That process is to randomly sample the nullset. Karl Schieneman & Thomas C. Gricks III, The Implications of Rule26(g) on the Use of Technology-Assisted Review, 2013 Fed. Cts. L. Rev. 239, 273 (2013)(“[S]ampling the null set will establish the number of relevant documents that are not being produced.”). Consequently, the question becomes whether sampling the null set is a reasonable inquiry under Rule 26(g) and proportional to the needs of this case under Rule 26(b)(1).

Rule 26(g) Certification
Judge Johnston takes an expansive view of the duties placed on counsel of record by Rule 26(g), but concedes that perfection is not required:

Federal Rule of Civil Procedure 26(g) requires all discovery requests be signed by at least one attorney (or party, if proceeding pro se). Fed. R. Civ. P. 26(g)(1). By signing the response, the attorney is certifying that to the best of counsel’s knowledge, information, and belief formed after a reasonable inquiry, the disclosure is complete and correct at the time it was made. Fed. R. Civ. P. 26(g)(1)(A). But disclosure of documents need not be perfect. … If the Federal Rules of Civil Procedure were previously only translucent on this point, it should now be clear with the renewed emphasis on proportionality.

Judge Johnston concludes that Rule 26(g) on certification applies to require the Elusion sample in this case.

Just as it is used in TAR, a random sample of the null set provides validation and quality assurance of the document production when performing key word searches.  Magistrate Judge Andrew Peck made this point nearly a decade ago. See William A. Gross Constr. Assocs., 256 F.R.D. at 135-6 (citing Victor Stanley, Inc. v. Creative Pipe, Inc., 250 F.R.D. 251, 262 (D. Md. 2008)); In re Seroquel Products Liability Litig., 244 F.R.D. 650, 662 (M.D. Fla. 2007) (requiring quality assurance).

Accordingly, because a random sample of the null set will help validate the document production in this case, the process is reasonable under Rule 26(g).

Rule 26(b)(1) Proportionality

Judge Johnston considered as a separate issue whether it was proportionate under Rule 26(b)(1) to require the elusion test requested. Again, the court found that it was in this large case on the pricing of prescription medication and held that it was proportional:

The Court’s experience and understanding is that a random sample of the null set will not be unreasonably expensive or burdensome. Moreover and critically, Defendants have failed to provide any evidence to support their contention. Mckinney/Pearl Rest. Partners, L.P. v. Metro. Life Ins. Co., 322 F.R.D. 235, 242 (N.D.Tex. 2016) (party required to submit affidavits or offer evidence revealing the nature of the burden)
Once again we see a party seeking protection from having to do something because it is so burdensome then failing to present actual evidence of burden. We see this a lot lately. Responding Party’s Complaints of Financial Burden of Document Review Were Unsupported by the Evidence, Any Evidence (e-Discovery Team, 8/5/18);

Judge Johnston concludes his “Order Establishing Production Protocol for Electronically Stored Information” with the following:

The Court adopts the parties’ proposed order establishing the production protocol for ESI with the inclusion of Plaintiffs’ proposal that a random sample of the null set will occur after the production and that any responsive documents found as a result of that process will be produced. Moreover, following that production, the parties should discuss what additional actions, if any, should occur. If the parties cannot agree at that point, they can raise the issue with the Court.

Conclusion

City of Rockford is important because it is the first case to hold that a quality control procedure should be used to meet the reasonable efforts certification requirements of Rule 26(g). The procedure here required was a random sample Elusion test with related, limited data sharing. If this interpretation of Rule 26(g) is followed by other courts, then it could have a big impact on legal search jurisprudence. Tara Emory in her article, Court Holds that Math Matters for eDiscovery Keyword Search goes so far as to conclude that City of Rockford stands for the proposition that “the testing and sampling process associated with search terms is essential for establishing the reasonableness of a search under FRCP 26(g).”

The City of Rockford holding could persuade other judges and encourage courts to be more active and impose specific document review procedures on all parties, including requiring the use of sampling and artificial intelligence. The producing party cannot always have a  free pass under Sedona Principle Six. Testing and sampling may well be routinely ordered in all “large” document review cases in the future.

It will be very interesting to watch how other attorneys argue City of Rockford. It will continue a line of cases examining methodology and procedures in document review. See eg., William A. Gross Construction Associates, Inc. v. American Manufacturers Mutual Insurance Co., 256 F.R.D. 134 (S.D.N.Y. 2009) (“wake-up call” for lawyers on keyword search); Winfield v. City of New York (SDNY, Nov. 27, 2017), where Judge Andrew Peck considers methodologies and quality controls of the active machine learning process. Also see Special Master Maura Grossman’s Order Regarding Search Methodology for ESI, a validation Protocol for the Broiler Chicken antitrust cases.

The validation procedure of an Elusion sample in City of Rockford is just one of many possible review protocols that a court could impose under Rule 26(g). There are dozens more, including whether predictive coding should be required. So far, courts have been reluctant to order that, as Judge Peck explained in Hyles:

There may come a time when TAR is so widely used that it might be unreasonable for a party to decline to use TAR. We are not there yet.

Hyles v. New York City, No. 10 Civ. 3119 (AT)(AJP), 2016 WL 4077114 (S.D.N.Y. Aug. 1, 2016):

Like a kid in the backseat of the car, I cannot help but ask, are we there yet? Hyles was published over two years ago now. Maybe some court, somewhere in the world, has already ordered a party to do predictive coding against their will, but not to our knowledge. That is a known unknown. Still, we are closer to “There” with the City of Rockford’s requirement of an Elusion test.

When we get “there,” and TAR is finally ordered in a case, it will probably arise in a situation like City of Rockford where a joint protocol applicable to all parties is involved. That is easier to sell than a one-sided protocol. The court is likely to justify the order by Rule 26(g), and hold that it requires all parties in the case to use predictive coding. Otherwise, they will not meet the  reasonable effort burdens of Rule 26(g). Other rules will be cited too, of course, including Rule 1, but Rule 26(g) is likley to be key.

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2 Responses to Elusion Random Sample Test Ordered Under Rule 26(g) in a Keyword Search Based Discovery Plan

  1. Michael McGinley says:

    Damn thorough, as always.

    Like

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