Accuracy is a measure of predictive performance.While the accuracy is straightforward, it can give a wrong idea of a model’s performance in many cases.To avoid this pitfall, data scientists prefer another metric to measure their model performance, called the f1-score.The f1-score is good for assessing models when there are few positives.However, the f1-score is an asymmetrical measure and can be very misleading when the proportion of successes is very high.A better solution is actually to use another metric called the p-4 score, which is considered the symmetrical expansion of the f1-score.The p4-score uses the harmonic mean of the precision, recall, specificity, and negative predictive value.The p-4 score is a very useful metric that assesses the performance of models better than the accuracy and the f1-score.The p4-score consistently gives more sensible results than other metrics.It fixes the main drawback of the f1-score and makes this metric far less misleading.