What operators (and/or) should I use between multiple "has not" query criteria?

For example, you want your query to bring back only those contacts who haven't clicked either of the following links, but it is bringing back contacts who clicked one of them:

When you use multiple has not query criteria in this situation, you should use the and operator between them (unless you do want to bring back contacts who have fulfilled both of the has not criteria). The query in the example brought back contacts who clicked link_1 because the query, with the has not criteria separated by or, brings back only those contacts who have not clicked both of those links. The following criteria:

Brings back only those contacts who have not clicked on either of those links. In other words, if someone clicked link_1, this query does not bring them back. And if someone clicked on signup_1, it also does not bring them back.

Why does it work this way?

Think of what a query with a positive statement has would do:

This query brings back people who clicked either link_1 or signup_1. But when it's changed to has not clicked, the operator (and/or) also needs to flip if you want to prevent contacts who meet one of the has not criteria lines from being included in the query results.

Example

The database has two contacts, Contact 1 and Contact 2. They were both sent email September 23 yesterday. That email had several links, but only two we care about for our query: link_1 and signup_1.

Contact 1 clicked on the link_1 link, while Contact 2 did not click on any link.

This criteria:

Brings back both Contact 1 and Contact 2. This is because, even though Contact 1 clicked on the link named link_1, they did not click on signup_1, and thus are included in the query results.

This criteria:

Brings back only Contact 2, since they have not clicked either link_1 or signup_1. Contact 1 is not included in the query results because they clicked on signup_1.

Note: Often, when combining multiple negative criteria with additional criteria you may need surround the negative criteria lines with parentheses.