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eDiscovery Processing: Searching

Searching electronic data is a methodology being employed during many phases in electronic discovery. Searching may be used to determine what data is collected; used within a review tool to prioritize review workflow; and used during the processing of electronic documents as a means to both cull and flag data prior to review. Proper understanding and implementation of searching technology and methodology can greatly impact the cost and time for any electronic discovery project, for both data processing and review.

Search terms to be applied to a given data collection are typically determined by the legal team, and approval is obtained by the opposing party and/or government regulators. The goal of the term list is to narrow the dataset to include all relevant documents and segregate documents that are non-responsive. The choice of terms is crucial to a successful result. Many suppliers of electronic discovery services can provide guidance on choosing terms that will result in the teams expected result. Additionally, by applying sampling techniques along with search term lists, the legal team can get a sense for the responsiveness of particular search terms. This is a deterministic method of data characterization.

Another method of organizing data is concept searching. When using concept searching, it is critical to understand how the concepts are created, as there are many different approaches to concept search on the market today. Careful consideration must be given to the ways in which concept searching is applied, because concept searching does not deterministically conclude the presence or absence of targeted data that may be evidence. Concept searching is not currently accepted as a means to eliminate data in a collected set prior to the review phase. Nonetheless, concept searching can be used to navigate a collected or responsive dataset. Therefore, concept searching can be effective in defining and refining search terms to be employed in a deterministic search in the processing phase. Finally, concept searching tools can be quite effective when applied to responsive datasets during the review phase.

Further, it is important to establish the method to be used during processing, because this will drive the data set (native files, metadata, body text, etc.) that is generated and supplied. The integration between processing technologies and review technologies must also be well established based on the requirements of the case. In some situations this can be a seamless transition from one phase to the next, and in other situations the requirements can make this transition complex. The flexibility of the vendor solutions, particularly for processing documents proactively, during organizational discovery where the requirements for a case may not be known during processing, is a key consideration.

Search Techniques

The search strategy can be determined by a number of factors. As a result, the appropriate search technique often varies from matter to matter. Below are a few examples of common search techniques.

Keyword Search

Keyword searches are a commonly used technique in the legal industry. Often, keywords are negotiated early prior to discovery to determine what content will be produced to the opposing side. Keyword searches require that the user knows precisely what she is looking for and are not always effective in investigative discovery.

Boolean Operators

Boolean operators such as "AND," "OR," and "NOT" are frequently employed to help further refine a keyword search.

Proximity Operators

Proximity or adjacency operators such as "NEAR," "PRE," and "WITHIN" are frequently employed to help further refine a keyword search.

Concept Search

While keyword searches are designed to return only the content that exactly matches the search, concept searching is designed to identify content that is conceptually similar to the search phrase.

Culling and Searching Considerations

Electronic discovery is often depicted as a linear process. In practice, a sound discovery process requires the flexibility to manage inputs from downstream activities (such as review) that impact upstream strategies and tactics (such as processing). Culling and searching occur throughout the discovery and review process and should be included as key components of the overall discovery strategy. Considerations for culling and searching include:

Sampling and Developing a Strategy

Gaining an initial understanding of the collection can be difficult, because the discovery team very infrequently receives all of the data at the same time or has the capability (or resources) to process all of the data at once. A common tactic for gaining insight into the collection is sampling. To obtain a reliable sample, consider collecting and processing key identified custodians first. Key custodians typically provide the most fertile content for exploration. A solid sample set can provide the team with a mini-collection for testing theories, identifying new custodians and data sources, and developing an appropriate processing and review strategy.

Early Review Benefits Culling and Searching

In discovery, time is always a factor. The processing strategy - including culling and searching - should ensure that a review team starts reviewing documents as soon as possible. Often a key document is found in review that can impact the entire discovery process. Being able to start review during the processing phase not only saves valuable time, but also can help further refine the culling and search strategy. Early identification of key documents is very useful in focusing the search strategy and is often a good way of identifying other useful search terms and techniques.

Identify the "Potentially Relevant"

Keyword searches should be tried and refined early in the process. It is useful to understand not only the hit rate, but also the relevancy rate of such searches. In other words, a keyword search that returns 15,000 documents that match the keywords but only yields three relevant documents may not be the best use of time or client resources. Understanding what makes a document relevant can translate into a more focused search strategy. Keywords are a great starting place, but a good search strategy will enable you to go after more meaningful documents faster by leveraging your knowledge of the matter or your discovery of key documents. Many tools today enable reviewers to use key documents to identify similar documents. Keyword searches can also be useful for generating "potentially privileged" sets of documents for early review.

Suppress, Don't Delete

During the culling phase, many documents will be removed from review consideration based on the criteria established by the review team and/or negotiated with the opposing counsel. When and if documents are removed, make sure that they are only suppressed from review and can still be accessed if needed later. Before culling begins, understand how culling decisions are tracked and how to audit the system(s).

Measure Success

Large-scale document review can be an arduous process with frequently changing requirements. Help clients understand progress and success by putting metrics and reporting in place at the beginning of review. If and when a surprise occurs, this will help clients understand the related impact on time and expense. During the culling and searching phase, common metrics include average volume per custodian, culling rates, and relevancy rates.

Is It Defensible?

Finally, a strategy that is not defensible is not a strategy. Ensure that an accurate and automated audit trail is in place. In addition, make sure that the attorneys can explain the culling and search strategy in layman's terms to clients, opposing counsel and a judge if necessary.

Source: EDRM: (

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