âDataset Cartography: Mapping and Diagnosing Datasets With Training Dynamicsâ, 2020-09-22 (; similar)â :
Large datasets have become commonplace in NLP research. However, the increased emphasis on data quantity has made it challenging to assess the quality of data. We introduce Data Mapsâa model-based tool to characterize and diagnose datasets. We leverage a largely ignored source of information: the behavior of the model on individual instances during training (training dynamics) for building data maps. This yields two intuitive measures for each exampleâthe modelâs confidence in the true class, and the variability of this confidence across epochsâobtained in a single run of training.
Experiments across 4 datasets show that these model-dependent measures reveal 3 distinct regions in the data map, each with pronounced characteristics. First, our data maps show the presence of âambiguousâ regions with respect to the model, which contribute the most towards out-of-distribution generalization. Second, the most populous regions in the data are âeasy to learnâ for the model, and play an important role in model optimization. Finally, data maps uncover a region with instances that the model finds âhard to learnâ; these often correspond to labeling errors.
Our results indicate that a shift in focus from quantity to quality of data could lead to robust models and improved out-of-distribution generalization.