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Title: Probing Saliency in Short Answer Scoring Models for Science Explanations
Recent work on automated scoring of student responses in educational applications has shown gains in human-machine agreement from neural models, particularly recurrent neural networks (RNNs) and pre-trained transformer (PT) models. However, prior research has neglected investigating the reasons for improvement – in particular, whether models achieve gains for the “right” reasons. Through expert analysis of saliency maps, we analyze the extent to which models attribute importance to words and phrases in student responses that align with question rubrics. We focus on responses to questions that are embedded in science units for middle school students accessed via an online classroom system. RNN and PT models were trained to predict an ordinal score from each response’s text, and experts analyzed generated saliency maps for each response. Our analysis shows that RNN and PT-based models can produce substantially different saliency profiles while often predicting the same scores for the same student responses. While there is some indication that PT models are better able to avoid spurious correlations of high frequency words with scores, results indicate that both models focus on learning statistical correlations between scores and words and do not demonstrate an ability to learn key phrases or longer linguistic units corresponding to ideas, which are targeted by question rubrics. These results point to a need for models to better capture student ideas in educational applications.  more » « less
Award ID(s):
1812660
NSF-PAR ID:
10286230
Author(s) / Creator(s):
; ; ;
Date Published:
Journal Name:
New York Academy of Sciences Natural Language, Dialog and Speech Symposium
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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