There is a recent surge of interest in using attention as explanation of model predictions, with mixed evidence on whether attention can be used as such. While attention conveniently gives us one weight per input token and is easily extracted, it is often unclear toward what goal it is used as explanation. We find that often that goal, whether explicitly stated or not, is to find out what input tokens are the most relevant to a prediction, and that the implied user for the explanation is a model developer. For this goal and user, we argue that input saliency methods are better suited, and that there are no compelling reasons to use attention, despite the coincidence that it provides a weight for each input. With this position paper, we hope to shift some of the recent focus on attention to saliency methods, and for authors to clearly state the goal and user for their explanations.
翻译:最近人们热衷于将注意力用作模型预测的解释,但对于能否将注意力作为模型预测的解释,有好坏参半的证据。虽然注意方便地给我们每个输入的象征一个分量,而且容易提取,但对于它用作解释的目的往往不清楚。我们发现,这个目标,无论是否明确声明,通常都是要找出哪些输入的象征与预测最相关,解释的隐含用户是模型开发者。对于这个目标和使用者,我们认为,投入的突出方法更合适,而且没有令人信服的理由利用注意力,尽管它为每一项投入提供了分量。我们想通过这份立场文件,把最近关注的重点转移到突出的方法上,让作者清楚地说明目标和用户的解释。