Web of Science does not feature a controlled vocabulary, and thus might be quicker to translate a responsive and topical search. One thing that it is a good idea to look out for in Web of Science, is that your field tags aren't bringing in wildly irrelevant results.
A good rule of thumb is to search using the topic field when conducting an alternatives search. The topic field includes the fields: title, abstract, author keywords, and keywords plus - in other words, the content-based fields. As a default, the Web of Science will search in all fields unless told otherwise. This will include fields like the author, author's organizational affiliation, and journal title, all of which are not relevant fields in a content-based search.
