Statements by someone with special knowledge on a given subject are known as

expert testimony.

Explanation:

Expert testimony refers to an opinion provided by a person who is deemed an expert because of specific education, skills, or experience in a specific subject. The expert is considered an authority in the subject, although he can still be called into question by other evidence or experts. Expert testimony is better used after entering a main point or subpoint of our argument, to better support and explain it.

answer; conflict perspective;

answer; broad features of society;