The domain expert/specialist is a key role for the success of any machine learning project and his specific value will be in the following areas:

• Definition of problem statement and help in correctly understanding the expectations of the solution
• Data preparation:
  • What are good candidates to be selected in feature engineering and kept as predictor attributes?
  • How to combine multiple objectives/attributes that would help solve the problem statement
  • How to sample to select the test set and training set
  • Help in data cleaning

• Progress monitoring and result interpretation:
  • Defining the accuracy of prediction required
  • Determining if more data/additional data is required, based on the progress made
  • Making a checkpoint in between and determine if the progress made is in alignment with the problem statement defined and the solution pursued is in line and can be further pursued in same lines or there is need to take a different path/re calibrate methods
• Continuous update and feedback on progress