Narrative or descriptive. I'm gonna go with narrative
Answer:
Valid evidence is based on facts or sound reasoning; invalid evidence is based on incorrect facts or faulty reasoning.
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Valid evidence is based on information that is closely related to the point being made; invalid evidence is based on contradictory or unconnected information.
This sentence would probably be a citation in APA style. Citations on research papers are very important since they give due credit to the original owner of the statement. Statements that don't have citations tells the readers that those statements are of the researcher/s alone which would be a problem for them if found out that it wasn't theirs to begin with. This would result to a work of plagiarism which is a grave sin in constructing research papers and is more equated with the act of stealing.