用amos分析数据的时候，软件说是非正定矩阵（具体如下），求高手指导，数据和模型出现了什么问题？谢谢

An error occurred while attempting to fitthe model. 拟合模型时出现一个错误。
The sample moment matrix is not positivedefinite. It could fail to be positive definite for any of the followingreasons: 样本协方差矩阵是非正定矩阵。由于下列原因不能正定。
1.The sample covariance matrix or thesample correlation matrix contains a data entry error.样本协方差矩阵或样本相关矩阵包含的数据有误。
2.The ovserved variables are linearlydependent (perhaps because the sample size is too small).观察变量因为样本太少产生线性相依的情形。
3.The sample covariance matrix or samplecorrelation matrix was computed from incomplete data using the method of‘pairwise deletion’.使用成对删除法时，从不完全的数据估计出样本协方差矩阵或样本相关矩阵。
4.The sample correlation matrix containscorrelation coefficients other than product moment correlations (such astetrachoric correlations). 与产生动差相关相比，样本相关矩阵包含其他无关相关系数。
For maximum likelihood estimation only, itmay be appropriate to check “Allow non-positive definite samples covariancematrices” in the “Analysis Properties” window, or to use the NonPositivemethod. 用最大似然法估计，应在“分析属性窗”口中适度检查“允许非正定样本协方差矩阵”，或使用非正定的方法。