Architecture-based methods either try to induce task-specific architecture during pre-training (task-specific methods), or aim at building a general pre-training architecture to fit all downstream tasks (task-agnostic methods) 
 Question: How architecture-based method handle obstacles in NLG?
task-specific architecture during pre-training (task-specific methods) aim at building a general pre-training architecture to fit all downstream tasks (task-agnostic methods)