The authors of pro & con or biased articles, books, or other sources have a specific bias and are trying to persuade the reader of a specific point of view in contrast to most academic articles that typically focus on topics in an objective manner that is meant to inform the reader.
Here are some characteristics of persuasive or biased articles:
Opinion or pro & con articles, books, or other resources with bias are ideal to use in argumentative papers or presentations.
They can also be used for informative research assignments, but you have to be more careful so as not to produce an unintentionally biased paper or presentation that is meant to be objective.
Most importantly, you have to be able to recognize if your source is biased and if it is appropriate for your assignment. If you aren't sure, ask your instructor.
These database are the best for opinion or pro & con topics. The good news is that it is clearly stated whether the articles are for or against the topic so you know going in what the bias is.
These open access sources all cover multiple topics. Some sites are more objective while others may have bias, so make sure to compare to other sources and evaluate critically. If you go to the About Us page on these sites you can learn more about what their bias is.