Neural Models for Measuring Confidence on Interactive Machine Translation Systems

Abstract

Reducing the human effort performed with the use of interactive-predictive neural machine translation (IPNMT) systems is one of the main goals in this sub-field of machine translation (MT). Prior works have focused on changing the human–machine interaction method and simplifying the feedback performed. Applying confidence measures (CM) to an IPNMT system helps decrease the number of words that the user has to check through the translation session, reducing the human effort needed, although this supposes losing a few points in the quality of the translations. The effort reduction comes from decreasing the number of words that the translator has to review—it only has to check the ones with a score lower than the threshold set. In this paper, we studied the performance of four confidence measures based on the most used metrics on MT. We trained four recurrent neural network (RNN) models to approximate the scores from the metrics: Bleu, Meteor, Chr-f, and TER. In the experiments, we simulated the user interaction with the system to obtain and compare the quality of the translations generated with the effort reduction. We also compare the performance of the four models between them to see which of them obtains the best results. The results achieved showed a reduction of 48% with a Bleu score of 70 points—a significant effort reduction to translations almost perfect.