TAME: Task Agnostic Continual Learning using Multiple ExpertsThe goal of lifelong learning is to continuously learn from non-stationary
distributions, where the non-stationarity is typically imposed by a sequence of
distinct tasks. Prior works have mostly considered idealistic settings, where
the identity of tasks is known at least at training. In this paper we focus on
a fundamentally harder, so-called task-agnostic setting where the task
identities are not known and the learning machine needs to infer them from the
observations. Our algorithm, which we call TAME (Task-Agnostic continual
learning using Multiple Experts), automatically detects the shift in data
distributions and switches between task expert networks in an online manner. At
training, the strategy for switching between tasks hinges on an extremely
simple observation that for each new coming task there occurs a
statistically-significant deviation in the value of the loss function that
marks the onset of this new task. At inference, the switching between experts
is governed by the selector network that forwards the test sample to its
relevant expert network. The selector network is trained on a small subset of
data drawn uniformly at random. We control the growth of the task expert
networks as well as selector network by employing online pruning. Our
experimental results show the efficacy of our approach on benchmark continual
learning data sets, outperforming the previous task-agnostic methods and even
the techniques that admit task identities at both training and testing, while
at the same time using a comparable model size.
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