[Retracted] Intelligent Performance Evaluation of Urban Subway PPP Project Based on Deep Neural Network Model

Table 4

Range of confidence values.

Confidence interval	Reference standards
0.85 ≤ a	Very high confidence level
0.65 ≤ a ≤ 0.85	High confidence
0.4 ≤ a ≤ 0.65	Moderate confidence
a ≤ 0.4	Not valid