The difference between biological and physical science is not that one is inexact, the oth

er exact, but in degree of exactness, this being related to the number of variables which must be dealt with simultaneously and the extent to which they can be controlled. In general, the biological sciences must deal with larger errors than the physical sciences; but this is not uniformly true, as the student will realize when he considers the accuracy of meteorological prediction or if he comprehends the meaning of the fact that the structural engineer considers it necessary very often to use a safety factor of two or three hundred per cent. The statistical principles of dealing with error of measurement, or in prediction and generalization, are the same whether the errors are large or small. Statistics is not a means of confusing issues that would otherwise be clear, nor a substitute for obtaining clear answers, but a means of checking and controlling conclusions by providing an estimate of the error to which a conclusion is subject.

What do statistics do for science？

A．They get rid of intuition,

B．They make it more logical.

C．They reduce everything to numbers.

D．They give an idea of the amount of error involved.