What is the best way to check the reliability and validity of a resource?

Analyze the author’s education and professional background.

Explanation:

Whenever you need to analyze the truth of a source, start by researching the author's background and professional experience to make sure the author knows what he is talking about and has the property to discuss about that subject. A person who has no education or professional experience in an area will not be able to give true and reliable information on a subject in that area. It will be easier for him to expose invented facts and false information that does not exist. This will not happen if the author is trained and has experience in that area, because the author will know the subject and give concrete information based on his or her background and experience.

julius caesar turned the roman republic into the roman empire by coming in and taking the "dictator" role during the time of a civil war (elites vs lower classes) winning battles and reputation, then declaring him dictator for life

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an era of negotiation.

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