Observations Conversations Publications and calculations Calculations and conversations
I gave my students this multiple choice question: Many things can contribute to the development of a theory. A student made a list of some things that might help scientists develop a theory. Observations Calculations Conversations Publications From the student's list, which must be used in the development of every theory?

Only one answer is correct among these 4 choices:
- Observations
- Conversations
- Publications and calculations
- Calculations and conversations

Could you tell me which one is correct?

Observations