"，L1 measure统计量理论上介于0~1之间"   

文献方法部分提到overal model fit probability 的概念，说明PSM的可靠性

“The propensity score was reliable because the overall model fi t probability was less than 10.4 and the area under the receiver operating characteristic curve (95% CI) was 0.76 (0.71 to 0.83).”。

请问这是什么意思？