Clarissa: The natural sciences would not have made such progress but for the power of mathematics. No observation is worth serious attention unless it is stated precisely in quantitative terms. Myungsook: I disagree. Converting observations into numbers is the hardest and last task; it can be done only when you have thoroughly explored the observations themselves. Clarissa and Myungsook's statements provide the most support for claiming that they disagree about whether ['successfully doing natural science demands careful consideration of observations not stated precisely in quantitative terms', 'not all observations can be stated precisely in quantitative terms', 'useful scientific theories require the application of mathematics', 'mathematics has been a highly significant factor in the advance of the natural sciences']