周志华《机器学习》对inductive bias定义如下:
机器学习算法在学习过程中对某种假设(hypothesis)的偏好,称为“归纳偏好”(inductive bias),或简称为“偏好”
书中举了例子,例如对一组数据进行拟合的曲线有无数种,其中有的比较“简单”(假设我们认为曲线更平滑意味着“更简单”),有的更复杂。例如一组可以用二次曲线来拟合的数据点,用更复杂的更高阶的曲线也可以拟合,那我们的模型应该选择哪条曲线/假设呢?这就是模型对假设的偏好问题。
在知乎一篇文章中又看到一个解释,也可以参考一下:
所谓的inductive bias,指的是人类对世界的先验知识,对应在网络中就是网络结构。
再举个论文中的例子,在《Recurrent Relational Networks》 一文中,网络结构如下图所示(具体训练过程见原文解释):
论文将该模型的inductive bias总结为:
This paper introduces a composite function, the recurrent relational network. It serves as a modular component for many-step relational reasoning in end-to-end differentiable learning systems. It encodes the inductive biases that
- objects exists in the world
- they can be sufficiently described by properties
- properties can change over time
- objects can affect each other and
- given the properties, the effects object have on each other is invariant to time.