Predicting multimodal presentation skills based on instance weighting domain adaptation

Abstract

Presentation skills assessment is one of the central challenges of multimodal modeling. Presentation skills are composed of verbal and nonverbal skill components, but because people demonstrate their presentation skills in a variety of manners, the observed multimodal features vary widely. Due to the differences in features, when test data samples are generated on different training data sample distributions, in many cases, the prediction accuracy of the skills degrades. In machine learning theory, this problem in which training (source) data are biased is known as instance selection bias or covariate shift. To solve this problem, this paper presents an instance weighting adaptation method that is applied to estimate the presentation skills of each participant from multimodal (verbal and nonverbal) features. For this purpose, we collect a novel multimodal presentation dataset that includes audio signal data, body motion sensor data, and text data of the speech content for participants observed in 58 presentation sessions. The dataset also includes both verbal and nonverbal presentation skills, which are assessed by two external experts from a human resources department. We extract multimodal features, such as spoken utterances, acoustic features, and the amount of body motion, to estimate the presentation skills. We propose two approaches, early fusing and late fusing, for the regression models based on multimodal instance weighting adaptation. The experimental results show that the early fusing regression model with instance weighting adaptation achieved \(\rho =0.39\) for the Pearson correlation, which presents the regression accuracy for the clarity of presentation goal elements. In the maximum case, the accuracy (correlation coefficient) is improved from \(-0.34\) to +0.35 by instance weighting adaptation.