Determine whether the nine metrics excluded for a non-positive-definite matrix are valid

Determine whether the nine code-quality metrics excluded because they caused a non-positive-definite correlation matrix measure the software-quality constructs they are intended to measure.

Background

The exploratory factor analysis excluded nine metrics because their inclusion caused a non-positive-definite matrix, making the correlation structure unsuitable for factor analysis. The paper therefore does not establish whether these metrics correspond to their intended constructs or whether they might be interchangeable with retained metrics.

Because the analysis could not evaluate these metrics, the authors explicitly describe the result as inconclusive. Resolving this question would require an alternative analysis, additional data, or a revised measurement model capable of assessing the excluded indicators.