For Question about Performance of a data science, statistical or machine learning model. Performace is a direct way to measure the efficiency of model. The Performance measure deals with time, accuracy and scalability for improve the model.
There are various metrics to calculate the efficiency of the data models itself. Methods include: confusion matrix, F1 score, Precision-Recall Curve, Receiver Operating Characteristics, among others. The idea is to see if the performance is better than the baseline models. It is important to consider that a model takes time to improve and that models are not foolproof.