Final answer:
User mining is not one of the techniques used in Web mining, which involves content mining, structure mining, and usage mining.
Step-by-step explanation:
The technique that is not used in Web mining is user mining. Web mining refers to the process of extracting useful information from the World Wide Web or web documents. The three techniques used in Web mining are content mining, which analyzes the content of web pages, structure mining, which examines the structure of web pages, and usage mining, which looks at the patterns of user behavior on the web.