Validity Searches Part 3: Conducting an opposition search that maintains budget, recall and precision

In the previous blog post, we learned that to identify good prior art documents in an opposition/validity search, it is important to correctly scope the search and select data collections. In this blog, we will learn about the specific points that a customer or a searcher should keep in mind before commencing an opposition/validity search.

Last year, my colleagues Mr. Urs Dommann and Mr. Ashutosh Pande wrote an excellent blog post about the concept of search quality (SQI) and how it relates to the economics of searches. The article very astutely explained how the cost of a search correlates with the expected recall and the precision that the customer wants in his search.

The principles mentioned in Urs and Ashutosh’s blog are applicable to all types of searches – including the opposition/validity searches that is the topic of the discussion in the current blog series. Using the lessons from that blog, and applying them to validity searches, would mean that before starting an opposition search, the customer should be clear on the extent of “risks” that he is willing to take vs. the budget that he has for the search. Risk in the context of an opposition/validity search would mean losing out on a good prior art document. For example, if the search is for a patent involved in an infringement lawsuit, then the stakes are very high, and the customer cannot afford to take any risks. In such a case, the customer would want all the prior art documents that can be identified, in order to make a sound case against the patent in the court.

To lower the risk in a search would entail identifying all the possible prior art documents – in other words, increasing the recall of the search. Typically, to increase the recall of a search, we need to spend more effort by analyzing more documents, running multiple search strategies with varying scopes, running the searches on different data collections, etc. This also increases the cost of the search as we try to increase the recall.

Specifically, the effort/cost vs. recall graph follows this trajectory:

Validity Search - Recall vs Cost

As you can see, the recall increases quite rapidly when the search is started, however it saturates after a sizable number of search strategies are run on different data collections. Also, the cost to the customer increases steadily as more strategies are run and the recall reaches closer to its maximum achievable value.

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So, what do we learn from this?

As a customer, and also as a searcher, it is always advisable to follow a phased approach while doing an opposition/validity search to optimize cost and get the best results within the available budget. Even if you have a sizable budget for the search, it is always advisable to follow a phased approach, as it leads to a controlled search and leaves room for course correction during the different phases of the search.

Precision is another important parameter to consider!

In addition, while preparing different search strategies during the course of the search, it is very important to give due importance to the precision of the search strategy as well. For example, a very broad search strategy on a data collection can increase the recall, however it reduces the precision of the search. On the other hand, multiple narrow search strategies can improve the precision, but the recall is not always high.

An experienced searcher usually fine-tunes the precision of the search strategy by using an optimum selection of keywords – genus vs. species; patent classification – class vs. subclass vs. group, text to be searched – abstract only vs. full specification, etc.

The recipe for a good search: a phased approach keeping budget, recall and precision in mind

Before beginning a search, due consideration should be given to three important parameters – available budget, expected recall, and expected precision. An example of a phased approach in a search including these three parameters could be:

Validity Search - Three parameter approach

Broadly speaking, based on our experience and the learnings that we have gathered over 18+ years in the IP and R&D search and intelligence industry, we usually recommend the following phased approach (sequential options) to our customers to identify the best prior art documents while performing an invalidity or opposition search:

Validity Search - recommendation phased approach

Ideally a customer should gradually move from Option 1 to 5. Even within a particular option, there could be sub-options. For example, Option 1 (or Option 2) mentioned above can be sub-divided into two options as highlighted in the earlier table in grey.

Following this kind of phased approach in a search always helps customers in finding the best prior art documents, while keeping the cost and the search quality under control.

Have you ever struggled to balance the cost and time with the precision of a search? Let us know what questions or comments you may have!

Shekhar Khanduja
Associate Vice President, IP and R&D Solutions Posts

Shekhar Khanduja is an associate vice president at Evalueserve, leading a team of highly-energetic IP and R&D searchers and drafting/prosecution experts. He aims to instil a passion for innovation in his team to continually improve IP and R&D solutions though small organic innovations and knowledge management. Raising quality and ideas to improve IP and R&D searches is a favorite goal – closely followed by experimenting in the kitchen to improve family recipes! Shekhar is hoping readers of this blog will join the conversation and share their ideas that he and his team can test internally to improve knowledge processes.

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