What is a plus or minus score used for?

The plus or minus score is used for:

Rating the criteria in each category of a rubric.

Explanation:

To understand this question we need to analyze the following. In case we wanted to analyze how many times a number is multiplied by a modifier we would not use the plus or minus score. We would also not use them to define the make an emphasis or provide a mood orientation to a certain line of dialogue. Neither to rate someone's opinion of our work. But we could use to fill the spaces of a rubric to rate each category of the criteria.

what is the question.. you are more likely giving us something to read with no question

what book are we talking about here