Quantifying the Task-Specific Information in Text-Based Classifications
share
Recently, neural natural language models have attained state-of-the-art performance on a wide variety of tasks, but the high performance can result from superficial, surface-level cues (Bender and Koller, 2020; Niven and Kao, 2020). These surface cues, as the “shortcuts” inherent in the datasets, do not contribute to the *task-specific information* (TSI) of the classification tasks. While it is essential to look at the model performance, it is also important to understand the datasets. In this paper, we consider this question: Apart from the information introduced by the shortcut features, how much task-specific information is required to classify a dataset? We formulate this quantity in an information-theoretic framework. While this quantity is hard to compute, we approximate it with a fast and stable method. TSI quantifies the amount of linguistic knowledge modulo a set of predefined shortcuts – that contributes to classifying a sample from each dataset. This framework allows us to compare across datasets, saying that, apart from a set of “shortcut features”, classifying each sample in the Multi-NLI task involves around 0.4 nats more TSI than in the Quora Question Pair.
READ FULL TEXT