English to Chinese Tech/Engineering IT (Information Technology) IT

The biggest challenge in machine learning (deep learning, in particular), is the availability of large volumes of labeled data to train the system. Two broad techniques can help address this: (1) synthesizing new data and (2) transferring a model trained for one task or domain to another. Techniques, such as transfer learning (transferring the insights learned from one task/domain to another) or one-shot learning (transfer learning taken to the extreme with learning occurring with just one or no relevant examples)—making ***them*** “lean data” learning techniques.
请问这个them是指？