Answer:
Based on scientific knowledge and tested trial
Step-by-step explanation:
Revision of any scientific concept is based on scientific knowledge that has been experimented, tested and confirmed through observation. For instance- any scientific concept that was lacking complete data set (unknown at the time of its explanation) , but now new or improved data has been established which shall lead to revision of accepted science explanations.
In most of the situation where a scientific concept is updated consists of data sets that is fragmentary and hence a bit of incomplete.