How many neurons?

Course Q&A Machine Learning Specialization Advanced Learning Algorithms
1

How do we decide how many neurons per layer to use (apart from input and output layer) in hidden layers and how many layers do we use in the model?

2

Hello @Apurva_Sen

Welcome to our community.

There is no 1 correct answer to this question. It involves a trial and error process and would require experimentation.

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3

Hi Shanup,
Are there any tricks or tips I should keep in mind when I try to design a neural network. I mean I have to start with something and then do some experiments to see if I am in the right direction or not. How do I decide on the initial ball park numbers?

4

A general rule:
Only add as much complexity as is needed to get good enough results.

Tips:

  • start with one hidden layer. Add more only if necessary.
  • for the number of units in the hidden layer, two rules-of-thumb are a) the square root of the number of input features, and b) the average between the input features and the output labels.
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