Opinions are like arseholes; everyone has one and they're frequently full of shit! A check list for interaction anything less will be dismissed... Evidence: Is it sufficient? Is it relevant? Is it accurate? ... Factual Evidence: Statements that are not disputed possessing a high degree of acceptance among experts. These can be examples and statistics... Examples: Are they representative? Are they understandable to the audience? ... Statistics: Are they from a trustworthy source? Are the terms clearly defined? Are comparisons between comparable things? Has any significant information been ommited? How recent are these data? ... Testimony/Expert opinions: Is the source of the opinion qualified on the subject? Is the source biased for or against their interpretation? Has the source bolstered claims with sufficient and appropriate evidence?