Evaluating the interaction fields of magnetic nanowires (MNWs) is of utmost importance for advancing their functionality in diverse applications including spintronic devices and nanomedicine. In recent years, several quantitative methods have been proposed and become inevitable tools to quantify the interaction fields and decouple their effects from the coercivity... However, the uncertainty of the attained results arose countless open questions leading to discrepancies among the literature. Here, we employ our novel experimental method, named the projection method, to resolve these discrepancies. Using a comparative analysis of the four most commonly used methods (hysteresis loops method, remanence curves method, first-order reversal curve method, and projection method), we unambiguously explicate the reliability and validity limits of these methods to elucidate the origin of the discrepancies. We show that the remanence curves method must solely be used for quantifying the interaction fields if they are considerably weaker compared to the coercivity. Furthermore, we show that both the remanence curves method and first-order reversal curve method fail to fully decouple the interaction fields effects from the coercivity, similar to the hysteresis loops method. (read more)