4.3. Verification results
The last item in this study is a verification conducted by the telecom provider for six months.
The provider investigated users whose monthly telephone fees exceed NT$2,000 and compared their data with the prediction results of the system.
The statistical results are shown in Table 6. During the comparison, the subjects investigated by the provider were considered to be the population; therefore, the recall of the providers was not calculated.
The method used to calculate the evaluation criteria in Table 6 is described as following Eqs. (2)–(4):