Research Tips — KeyCite Depth of Treatment in westlaw Canada

KeyCite "Depth of Treatment" in westlaw Canada

When noting up a case, especially a leading case, the result list can be very large. KeyCite Canada has always included extensive filters to help users manage these large result lists. With the introduction of westlaw Canada, users will have a new tool to help them quickly identify the most relevant results.


The majority of citing references do not include an extensive discussion of the cited case. Rather, the cited case is often only mentioned in passing. These “referred to” citing references do not provide researchers with much information. The most relevant citing references are those that include a discussion of the cited case. These citing references can help a researcher in a variety of ways, from interpreting the cited case to finding a useful way to distinguish it. 

KeyCite Canada on westlaw Canada now includes “Depth of Treatment” information to help researchers quickly identify the citing cases that include these significant discussions. Citing cases are programmatically assigned a depth of treatment value from one to four, with four being the highest. The value is based upon the number of times the cited case is mentioned.   

It is important to note that the Depth of Treatment value does not speak to the nature of the treatment. It does not provide any information about whether the treatment is negative or positive. It merely provides information about how much discussion of the cited case a citing reference contains. 

Depth of treatment can be used as the sort order for case law citing references. It can also be used as a filter; it can be combined with other filters to produce highly tailored results.