Personalized Difficulty and Topic Authority can be found in Topic Inventory and Reflect.
Unlike keyword difficulty, a general metric about how hard it is for everyone to rank, Personalized Difficulty shows how hard it is for you to rank for a topic.
Topic Authority is Personalized Difficulty’s close companion and you can think of it as your competitive advantage. The more authority you have, the less content you need to remain competitive.
Topic Authority considers the content on your site. Specifically, it examines the amount coverage of a topic and how well your pages about that topic perform, both now and historically. A site that publishes a great deal of high-performing expert-level content around a specific topic will have higher authority on that topic, relative to the competition.
Likewise, a site that publishes no content, or a small amount of poorly-performing content can have negative authority. It’s not a penalty, it’s just a way of indicating your authority is lagging behind the competition.
When red and negative, your topic authority is staggering behind the competition.
When green and positive, your topic has authority and the higher the number the more competitive your site is when publishing content around this topic.
Learn more in What is Personalized Keyword Difficulty and Why You Need It