Automated Short-Answer Grading using Semantic Similarity based on Word Embedding

Abstract

Automatic short-answer grading (ASAG) is a system that aims to help speed up the assessment process without an instructor’s intervention. Previous research had successfully built an ASAG system whose performance had a correlation of 0.66 and mean absolute error (MAE) starting from 0.94 with a conventionally graded set. However, this study had a weakness in the need for more than one reference answer for each question. It used a string-based equation method and keyword matching process to measure the sentences’ similarity in order to produce an assessment rubric. Thus, our study aimed to build a more concise short-answer automatic scoring system using a single reference answer. The mechanism used a semantic similarity measurement approach through word embedding techniques and syntactic analysis to assess the learner’s accuracy. Based on the experiment results, the semantic similarity approach showed a correlation value of 0.70 and an MAE of 0.70 when compared with the grading reference.

Keywords

• automated grading
• short answer
• semantic similarity
• syntax analysis
• word embeddings