Features – KeySearch, West's Key Number System, and Lexis' Search Advisor

Cindy Curling is the Electronic Resources Librarian for Fried, Frank, Harris, Shriver & Jacobson in Washington, D.C. and has been teaching research strategies to legal staff since 1995. This year she helped found the Legal Research Training Focus Group for the Law Librarians’ Society of the District of Columbia to encourage the exchange of training resources and ideas in the greater Washington area.


Recently, West introduced KeySearch, an alternative and streamlined method to access case law by topic and a product which will compete with Lexis’ Search Advisor. For most of its history as a legal research resource, West has maintained its dominance. In part, this is because the Key Number System has so thoroughly classified case law, allowing users familiar with the system to quickly find cases on point. So why introduce KeySearch? Because Key Numbers are complicated and underused and KeySearch is more user-friendly without sacrificing some of the sophistication of the traditional system.

I recently attended a Westlaw class for power searchers, primarily law firm librarians, where the presenter asked whether the attendees thought that the Key Number System was still useful. The general response among the librarians was positive, but it was noted that since so many of our younger attorneys – those doing the most online research – had rarely used the West system in print, they were more likely to use full-text term searching.

Now, as a trainer and end-user, this drives me crazy, because I know they are not searching as efficiently as they could be. Advanced users, especially attorneys familiar with headnotes and Key Numbers from years of experience working with print digests and case law, are more likely to combine the Key Number System with full-text searching to maximize their online advantage. Considering the complexity of the system, it is not an easy prospect even for them.

Still, they use it because working with topics and Key Numbers encourages them to identify the broad concepts behind their legal research, expanding on the terms directly relevant to their specific circumstance. Also, using the Key Number system minimizes the number of off-topic results. Ambiguous or common terms, like “will”, are never an issue when you use the correct Key Number. When a topic or Key Number is used in a case, it definitely deals in some significant part with the correct concept, rather than simply mentioning the term as is often the case with a full-text search. Advanced users can then further refine their results by adding in additional terms.

So, yes, power users still think the system is useful, but we all agreed that it was intimidating to attorneys who were unfamiliar with the West print products.

Search Advisor v. the Key Number System

To understand why KeySearch is important, it helps to see it against the background of Search Advisor and the Key Number System. Lexis also sees classifying case law by topic as useful; in late 1999 it introduced Search Advisor, a product meant to compete directly with topics and Key Numbers. Lexis promotes Search Advisor as superior to straight topic and Key Number searching for the following reasons:

Lexis’ Search Advisor Features

Traditional West System

Search Advisor applies over all cases, not just published cases, as well as to some secondary materials.

Key Numbers are only applicable to materials annotated by the West editors.

Search Advisor is more current. The Lexis system is based on an automated “patented information algorithm” so that it incorporates new cases as soon as they are available online. Yet Lexis, like West, uses an editorial team to create, modify and cross-reference topic information so the system is not without the guiding hand of expert human researchers.

It takes a few weeks for a new case to go through the West editorial process where enhancements like Key Numbers and headnotes are added.
Search Advisor is more flexible and responsive to the changing state of the law because it isn’t confined by a strict classification structure. Wholesale reclassification of terms in the West system does happen, but it is a huge logistical challenge. Previous print editions can not change, and reclassification will always require heavy cross-referencing between old and new topics and Key Numbers. Changes happen, but they are carefully chosen and do not occur unless absolutely necessary.
Search Advisor compares terms in its hierarchy only to terms within the texts of each case. West editors add additional terms not used in the case text .

Whether the last is truly an advantage is open to interpretation. The Lexis view is that the researcher should directly interpret the word of the court, so the words you see in a summary are the words you’ll see in the case itself. The West view is a little more expansive. A West editor may alternate terms in the headnotes and choose topics and Key Numbers which are not strictly identical to the terms in the case, but which are close parallels. When a user runs a search for a Key Number, she may get a few red herrings among the results, but this system does allows users to find cases incorporating a broader range of similar concepts. Either way, experienced researchers know they must read every case to determine whether or not it will be applicable to an argument.

Ultimately, though, the biggest advantage of Search Advisor over the old West system is that it was designed to be more intuitive, using a term-based structure rather than a numbered hierarchy. West Key Numbers, helpful as they are, take some getting used to. As with any formal classification system, the Key Numbers can work as an extremely useful shorthand searching tool for users intimate with the structure. Otherwise, the numbers certainly require some effort to use and are not intuitive at all.

Key Search

That brings us back to KeySearch. The Key Number System starts with a base of seven extremely general legal categories, breaks these down into over 400 topics, and then uses the Key Numbers within each topic for even greater specificity – around 100,000 issues. KeySearch helps the novice by interpreting that hierarchy in terms only, almost like using a digest index. Like Search Advisor, it allows a novice user to work within a Yahoo-like subject hierarchy in order to identify cases on point. However, since KeySearch is based on the topic and Key Number System, it also provides advantages to expert Westlaw searchers.

The topics represent nearly 10,000 legal issues, a more streamlined group than the original Key Number System, though, claims West, more than the number of issues addressed within Search Advisor, now around 4,100. For each issue, a West expert has formulated a matching query. Essentially, a user drills down through the topic hierarchy until he gets to an issue specific enough for his research. If the user is not sure where an issue falls in the hierarchy, he can run a general keyword search and the result will show any category that includes his term(s).

The queries themselves are difficult to compare because the Search Advisor queries are hidden. With KeySearch you can opt to see the pre-formulated queries for each issue by clicking to “View Query”. Queries may consist of one or several Key Numbers, a combination of Key Numbers and text, or text only, depending in part on whether or not the database searched is one which contains topic and Key Number references. This assures that families of Key Numbers categorized under different topics are pulled together for the broadest relevant search and that any additional terms not treated in the topic and Key Number System are included. That makes KeySearch responsive to new legal concepts. Also, users can now apply the major topic and Key Number concepts over unpublished cases and secondary materials.

Queries combining Key Numbers for similar concepts which are categorized under separate topics are difficult to create, even for attorneys who are familiar with the system. Since KeySearch has pre-configured the queries, using it can be a huge time-saver. Beyond that, attorneys who are expert searchers can not only see the logic used by the West experts, but also change or add to the pre-configured queries as necessary.

Though the search logic is not visible until requested, novice searchers can, if they choose, see the queries too. However, without some grounding in the Key Number System, they are more apt to simply trust what the West experts have pre-configured. When I first looked at KeySearch, the only way to see an explanation of the Key Numbers in a search seemed to be to go to the Key Number Service and look them up separately. Evidently, the ability to view an explanation of the Key Number was available, but it was via a small, unlabeled yellow button on the white background next to the search box. I missed it, and I was looking for it, so I was happy to hear that a recent modification now places the button near the query editor prompt and that it is labeled “Key Number information about this query”. Definitely an improvement, and potentially helpful for novice users as it lets them learn more about the Key Numbers as they search.

Key Search and Search Advisor

Though West was developing KeySearch before Search Advisor was released, there are definitely some parallels, most of which place West squarely back on the competitive front:

  • KeySearch allows access to most of West’s secondary materials, though not to general legal news as does Search Advisor. When you choose a topic, applicable secondary materials are available to search from the same screen where you can search case law. According to West, news materials are not included since they are not likely to use the sort of legal terminology which makes up the queries derived from the topic and Key Number System.
  • KeySearch is more current than the topic and Key Number System. User searches run on any database included on Westlaw for that topic or sub-topic, including new unedited cases. The Key Number queries, however, are only meaningful on West annotated cases with headnotes and Key Numbers as they become available from the editorial process.
  • KeySearch is much more flexible and responsive to the vagaries of the law than the topic and Key Number System since text can be added to modify queries without changing the formal classification scheme.

Room for Improvement?

One quibble I have with KeySearch is minor. I would like to see some news element incorporated into the system. While the Key Number based-queries would be meaningless, some legal newspapers use the type of vocabulary searched in the non-published case law queries. If I were working on a case and a similar case came to trial as I was doing my research, I would want to know, especially in a developing area of law.

My other complaint is more serious. Having to search separately for reported and unreported cases significantly detracts from the time saving aspects of the service which West is promoting. Happily, resolving this issue, according to West, is a major priority and one which they hope to see resolved soon, possibly in the fourth quarter of 2001.

Summing Up

I am not a specialist in taxonomies or classification, and approached this review very much from the standpoint of the user and the trainer. I did not compare one system directly to the other search to search. I used each system, reviewed the documentation available on each product, and spoke to developers at both services1. Both the Lexis and West developers were careful to point out to me that each system works differently, and results therefore would vary widely from service to service. That, along with not being able to see the logic in Search Advisor, dissuaded me from a direct comparison. Beyond that, it seems the aim of neither service is to replace regular Boolean or natural language approaches where strict comparisons are more viable. Rather, the goal is to introduce an interface to make searching simpler and more efficient, especially for the novice. In that context, they both do well.

Overall, I think the advanced elements give KeySearch a slight edge. KeySearch balances its user-friendliness with a sophistication that will provide efficiencies to advanced users, and the interface works well and is friendly enough to help novices. The topic and sub-topic lists and queries encourage users to think about the elements of their case in the context of the body of law, bringing the process of searching back from the mechanical toward intellectual concepts.

I also appreciate the extra depth of issues available in KeySearch, though again, I was informed by both services that their products are not about numbers. Instead each is an attempt to make searching as streamlined and friendly as possible while not missing any important cases or secondary materials. Be that as it may, Lexis targets its product mainly at novices and people working in an unfamiliar area of law. Lexis opted not to show its search logic and to make its hierarchy of terms relatively compact. Search Advisor is a great product, and it makes a good starting point for most legal research, but it is probably not detailed enough to be of much extra value to an advanced searcher.

Before the introduction of Key Search, I think most Westlaw users either did not use the topic and Key Number System online or used it in a very limited fashion. With KeySearch, novice users can be much more efficient and advanced searchers are able to take maximum advantage of the system without spending an inordinate amount of time developing queries. KeySearch may persuade a few Lexis users to switch to Westlaw, especially Key Number fans who have been using Search Advisor. Any current Westlaw user not familiar with topics and Key Numbers should definitely try KeySearch, and even the most advanced users will benefit from viewing the search logic.

End Notes

1 At Westlaw: Daniel Dabney, Senior Director for Research and Development , and at Lexis: Harry Silver, Senior Director of Indexing and Search Programs and Leslie Denton, Program Manager for Legal Classification and Indexing. < back to text>
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