Video quality metrics are intended to provide calculated values that are strongly correlated with viewer subjective assessments. This Recommendation provides: a) methods for curve fitting VQM objective values to subjective data in order to facilitate the accuracy calculation and to produce a normalized objective value scale that can be used for cross-correlation between different VQMs; b) an algorithm (based on statistical analysis relative to subjective data) to quantify the accuracy of a given VQM; c) a simplified root mean square error calculation to quantify the accuracy of a VQM when the subjective data has roughly equal variance across the VQM scale; d) a method to plot classification errors to determine the relative frequencies of "false tie", "false differentiation", "false ranking", and "correct decision" for a given VQM.