The best way to evaluate a claim's truth or falsity is to search for evidence that either supports or refutes it. In keeping with the social science category of this question, if one claims, for example, that poverty contributes to crime, one would need to do research that investigated the socioeconomic backgrounds of people who had been convicted of certain crimes. If there was a correlation between the two, then one could begin to tentatively make assertions about the accuracy of the claim. If there was not, or if the correlation was not a strong one, then one would need to revise their claim. Either way, the researcher would have to also investigate other factors that might tend to complicate the claim. If, for example, a correlation could be established between poverty and crime, but there was an equally strong correlation between lack of education and crime, then one would need to think about how these factors are related.