The goal of writing a persuasive essay is to persuade or convince the reader to believe something. Writers do this through the use of logical arguments and emotional appeals.
Information comes from lots of different sources.
Every source has its own way of presenting information. Some information is reliable and factual. Some is guesswork and opinion. And some isn't useful at all. The trick is to know the difference.
Here are some questions to help you evaluate the sources:
Information taken from Opposing Viewpoints tip sheet.