If you don't have a loss, the derivative of what would you get ?

[XinshaoAmosWang]

https://www.reddit.com/r/MachineLearning/comments/ha0k5u/r_source_codes_for_general_examplelevel_weighting/fv1av1l?utm_source=share&utm_medium=web2x

Deep learning models are optimised by SGD.
1. Is a loss function necessary for deriving the gradient used for back-propagation?
2. What is the righter way to weight training data points?
3. When a training set contains a higher label noise rate, we should focus on easier training examples for better generalisation!

Code releasing: https://xinshaoamoswang.github.io/blogs/2020-06-14-code-releasing/

For a defined optimisation objective, e.g., maximising p(y|x) towards one, we can have so many loss functions, e.g., absolute error |1-p(y|x)|, square error (1-p(y|x))^2.

Here, 1st item means that there is no need to care the format of loss functions. Instead, all we need is to design the gradient directly to optimise the defined ultimate optimisation objective.

We discussed that it is more intuitive and can be easily interpreted from the angle of example weighting (2nd item).