In the beginning, each character has personal reasons for wanting to go to california. in what ways do each individual's goal change? which people grow to see a larger purpose in life? what factors contribute to their changes?

The family heads west for economic reasons; they need to build a new life and find an opportunity to make a living. They leave for California based on a flyer advertising the workers are needed, but it is fraudulent. It will be awhile before everyone figures this out.

Each of the family members has a different reason for going. Most of the family stays together for that reason only; to keep the family together. Pa has no role whatsoever, he's going through the motions and doesn't make any big decisions. Ma is probably the first to start second guessing the decision. Gradesaver has a great study guide for this unit. I'm posting a direct link below. You should be able to find the details you need there, either within the summary or in the character analysis.