In NUVI, the sentiment is what determines whether or not a mention is positive, negative, or neutral. Based on an algorithm, particular words and phrases may be marked as positive or negative.
With sentiment categories, users have the ability to get more accurate sentiment with a set list of words that are specific to that one category.
To select a category, when creating a monitor, there is a section labeled Sentiment Categories.
As NUVI continues to update, more categories will be available. If there isn't a category suitable for the user, they can submit a request here on the website. For now, the image below has the available categories: Airlines, E-commerce, Healthcare, Hotels, Restaurants, and Workplace.