Hi all,
This is just a request for confirmation of my understanding of bias in the dot product model.
18.What is the use of bias in a dot product model?
and related to this
- Does sorting the movie biases give the same result as averaging overall movie ratings by movie? Why / why not?
My understanding of bias in this case is that it is a latent factor that is inherent in the user or item itself.
In contrast, the other kind of latent factor is a result of the interaction of an item with a user and vice versa (i.e. the latent factors of an item are multiplied with the latent factors of a user)
Related to this, the reason why the ranking based on the movie biases can be different from the ranking based on the average movie ratings is because the average movie rating is the result of the combination of latent factors of both users and items (including user and item biases), while sorting via movie biases alone removes the user’s bias as a factor in the ranking.
What do you think of my formulation?
(BTW, this question arose around our ongoing study group re-reading discussion lead by @gansme and @marii here - new participants stll welcome!)
PS.
The bias I discuss in the dot product model is slightly different from the normal bias
we deal with in a conventional NN – I consider the bias as a parameter associated with the neuron itself, whereas the weights are parameters associated with the connections between the inputs and the neuron.