What can we help you with?

What can we help you with?

Stemming and Wildcard 101

What is Stemming?

If you have never come across stemming before, you can think of it as being a method in which you can search for a word and have related words returned. Thinking of it more technically, it is a method of producing morphological variants of a root or base word. It can reduce words such as "spraying", "sprayable", "sprayed" or "sprays" to the root word of "spray". This will allow you to search for a base word and not have to additionally include variants of that word in your query.

Recently, we introduced an update to our stemming logic which is more advanced and will provide you with more accurate and advanced results for the queries you perform. 

You can find more information on benefits of new stemming logic here.


This is a more selective form of stemming. If you only want certain words to be stemmed, you can add an asterisk at the end of the word you want to be stemmed.

There are two wildcards, the question mark ? and the asterisk *. Wildcards can only be used in the middle or at the end of the word. One ? represents one character, the * represents an unlimited number of characters, i.e.:

car? (will give you cars, card, care…)

car(will give you car, carton, carbon, cardio…)

English stemming is automatically switched on, so if you search in English you will automatically be encompassing variables of your search term. This can be very broad when searching for short words especially, for instance searching for “cat” will get you patents that mention “location”. Much like Google and Bing, PatSnap will search up to 1500 wildcard variations per query. The limit is in place to ensure that you only get the most relevant search results returned.


Was this article helpful?

6 out of 9 found this helpful

Have more questions? Submit a request

Return to top