The first step in understanding what terms trigger topic results is inspecting topic terms. You can do so by opening any topic page and clicking on "# terms" link in the top right corner.
If you spot a term that you don't want to track in your support conversations, you can remove it from the topic by clicking Remove.
When a term is removed, it will stop contributing to the topic results in terms of mentions, sentiment or showing up in conversation excerpts.
Convert a term to a topic
If you spot a term that you want to track but as part of a separate topic you can convert it to a topic by clicking Convert to topic.
This will remove it from the current topic and create a separate topic with the selected term only.