Short Answer Detection for Open Questions: A Sequence Labeling Approach with Deep Learning Models

Abstract

Evaluating the response to open questions is a complex process since it requires prior knowledge of a specific topic and language. The computational challenge is to analyze the text by learning from a set of correct examples to train a model and then predict unseen cases. Thus, we will be able to capture patterns that characterize answers to open questions. In this work, we used a sequence labeling and deep learning approach to detect if a text segment corresponds to the answer to an open question. We focused our efforts on analyzing the general objective of a thesis according to three methodological questions: Q1: What will be done? Q2: Why is it going to be done? Q3: How is it going to be done? First, we use the Beginning-Inside-Outside (BIO) format to label a corpus of targets with the help of two annotators. Subsequently, we adapted four state-of-the-art architectures to analyze the objective: Bidirectional Encoder Representations from Transformers (BERT-BETO) for Spanish, Code Switching Embeddings from Language Model (CS-ELMo), Multitask Neural Network (MTNN), and Bidirectional Long Short-Term Memory (Bi-LSTM). The results of the F-measure for detection of the answers to the three questions indicate that the BERT-BETO and CS-ELMo architecture obtained the best effectivity. The architecture that obtained the best results was BERT-BETO. BERT was the architecture that obtained more accurate results. The result of a detection analysis for Q1, Q2 and Q3 on a non-annotated corpus at the graduate and undergraduate levels is also reported. We found that for detecting the three questions, only the doctoral academic level reached 100%; that is, the doctoral objectives did contain the answer to the three questions.