Randomness is the Root of All Evil: More Reliable Evaluation of Deep Active Learning

Using deep neural networks for active learning (AL) poses significant challenges for the stability and the reproducibility of experimental results. Inconsistent settings continue to be the root causes for contradictory conclusions and in worst cases, for incorrect appraisal of methods. Our community is in search of a unified framework for exhaustive and fair evaluation of deep active learning. In this paper, we provide just such a framework, one which is built upon systematically fixing, containing and interpreting sources of randomness. We isolate different influence factors, such as neural-network initialization or hardware specifics, to assess their impact on the learning performance. We then use our framework to analyze the effects of basic AL settings, such as the query-batch size and the use of subset selection, and different datasets on AL performance. Our findings enable us to derive specific recommendations for the reliable evaluation of deep active learning, thus helping advance the community toward a more normative evaluation of results.