Learning with not Enough Data Part 3: Data Generation
Lilian Weng
The article discusses two approaches for generating synthetic training data when real data is scarce: data augmentation through transformations of existing samples, and generating new data using pretrained models like large language models. Data augmentation modifies input format while preserving semantic meaning, and few-shot prompting enables language models to learn from limited examples without additional training. This addresses the challenge of training machine learning models with insufficient real-world data.
Why it matters
Here comes the Part 3 on learning with not enough data (Previous: Part 1 and Part 2). Let’s consider two approaches for generating synthetic data for training. Augmented data. Given a set of existing training samples, we can apply a variety of augmentation, distortion and transformation to derive new data points without losing the key attributes. We have covered a bunch of augmentation methods on text and images in a previous post on contrastive learning. For the sake of post completeness, I duplicate the section on data augmentation here with some edits. New data. Given few or even no data points, we can rely on powerful pretrained models to generate a number of new data points. This is especially true in recent years given the fast progress in large pretrained language models (LM). Few shot prompting is shown to be effective for LM to learn within context without extra training. Data Augmentation The goal of data augmentation is to modify the input format (e.g. text wording, visual a