2. The method of claim 1 , wherein: the tracking the activity includes determining that a category constraint for the first query is the same as a category constraint for the second query; and the counting the number of search events is based on the determining that the category constraint for the first query is the same as the category constraint for the second query.
2. The method of claim 1 , wherein: the tracking the activity includes determining that a category constraint for the first query is the same as a category constraint for the second query; and the counting the number of search events is based on the determining that the category constraint for the first query is the same as the category constraint for the second query. 3. The method of claim 2 , further comprising causing display of an indication that the category constraint for the first query is the same as the category constraint for the second query via a search user interface on the client device.