“…These works can be categorized into three major families: 1) architectural strategies, 2) rehearsal strategies, 3) regularization strategies. Architectural strategies [1,2,25,29,30,51] keep the learned knowledge from previous tasks and acquire new knowledge from the current task by manipulating the network architecture, e.g., parameter masking, network pruning. Rehearsal strategies [17,27,37,42,50] replay old tasks information when learning the new task, and the past knowledge is memorized by storing old tasks' exemplars or old tasks data distribution via generative models.…”