新手上路，请教各位前辈一问题，在SPSS中进行信度分析时，输出结果提示警告：
Warnings
The covariance matrix is calculated and used in the analysis.
The determinant of the covariance matrix is zero or approximately zero. Statistics based on its inverse matrix cannot be computed and they are displayed as system missing values.
   请问这是什么问题造成的，其次这样的话，其信度分析有无影响。
   谢谢各位！