Provable Lifelong Learning of Representations
- URL: http://arxiv.org/abs/2110.14098v1
- Date: Wed, 27 Oct 2021 00:41:23 GMT
- Title: Provable Lifelong Learning of Representations
- Authors: Xinyuan Cao, Weiyang Liu, Santosh S. Vempala
- Abstract summary: We propose a provable lifelong learning algorithm that maintains and refines the internal feature representation.
We prove that for any desired accuracy on all tasks, the dimension of the representation remains close to that of the underlying representation.
- Score: 21.440845049501778
- License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
- Abstract: In lifelong learning, the tasks (or classes) to be learned arrive
sequentially over time in arbitrary order. During training, knowledge from
previous tasks can be captured and transferred to subsequent ones to improve
sample efficiency. We consider the setting where all target tasks can be
represented in the span of a small number of unknown linear or nonlinear
features of the input data. We propose a provable lifelong learning algorithm
that maintains and refines the internal feature representation. We prove that
for any desired accuracy on all tasks, the dimension of the representation
remains close to that of the underlying representation. The resulting sample
complexity improves significantly on existing bounds. In the setting of linear
features, our algorithm is provably efficient and the sample complexity for
input dimension $d$, $m$ tasks with $k$ features up to error $\epsilon$ is
$\tilde{O}(dk^{1.5}/\epsilon+km/\epsilon)$. We also prove a matching lower
bound for any lifelong learning algorithm that uses a single task learner as a
black box. Finally, we complement our analysis with an empirical study.
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