The Web Can Be Your Oyster for Improving Language Models

Pretrained language models (PLMs) encode a large amount of world knowledge. However, as such knowledge is frozen at the time of model training, the models become static and limited by the training data at that time. In order to further improve the capacity of PLMs for knowledge-intensive tasks, we consider augmenting PLMs with the large-scale web using search engine. Unlike previous augmentation sources (e.g., Wikipedia data dump), the web provides broader, more comprehensive and constantly updated information. In this paper, we present a web-augmented PLM -UNIWEB, which is trained over 16 knowledge-intensive tasks in a unified text-to-text format. Instead of simply using the retrieved contents from web, our approach has made two major improvements. Firstly, we propose an adaptive search engine assisted learning method that can self-evaluate the confidence level of PLM's predictions, and adaptively determine when to refer to the web for more data, which can avoid useless or noisy augmentation from web. Secondly, we design a pretraining task, i.e., continual knowledge learning, based on salient spans prediction, to reduce the discrepancy between the encoded and retrieved knowledge. Experiments on a wide range of knowledge-intensive tasks show that our model significantly outperforms previous retrieval-augmented methods. Our code and data can be accessed at this link https://github.com/RUCAIBox/UniWeb * Corresponding author Question Which popular Korean show was recently green lit for a new season? Answer Squid Game Wikipedia There are no results for the question. Web [...] Netflix announce Sunday that the wildly popular South Korean show is green lit for a second season. "And now, Gi-hun returns" "The Front Man returns. Season 2 is coming." "Squid Game" is a fictional drama from South Korea in which contestants who are desperately in need of money play deadly children's games to win cash prizes. [...] URL: https://www.cnn.com/2022/06/1 2/media/squid-game-season-2/index.html T5 w/o Web The Walking Dead T5 w/ Web Squid Game Self-Evaluation Retrieve? Commonsense Reasoning Commonsense QA Slot Filling Dialogue Fact Checking Natural Language Inference The football manager who recruited David Beckham managed Manchester United during what timeframe? 1995-96 Manchester United F.C. season The 1995-96 season was Manchester United's fourth season in the Premier League .....