Supporting ESL Writing by Prompting Crowdsourced Structural Feedback.

Writing is challenging, especially for non-native speakers. To support English as a Second Language (ESL) writing, we propose StructFeed, which allows native speakers to annotate topic sentence and relevant keywords in texts and generate writing hints based on the principle of paragraph unity. First, we compared our crowd-based method with three na¨ıve machine learning (ML) methods and got the best performance on the identification of topic sentence and irrelevant sentence in the article. Next, we evaluated the StructFeed system with two feedback-generation mechanisms including feedback generated by one expert and by one crowd worker. The results showed that people who received feedback by StructFeed got the highest improvement after revision.