What is an uncontrolled factor?

Question

what is an uncontrolled factor, is it a factor that u cant control?

If there was a marathon, what are the uncontrolled factors?

Answer 1

An uncontrolled factor (in an experiment, for instance) is one that probably affects the measured quantity, varies from individual or with time during the experiment, and basically cannot be manipulated by the operator.

During a marathon weather is certainly an uncontrolled factor.  This can cause running times to be faster or slower from year to year due to the degree of favorability of the temperature, wind, rainfall, etc.  Other uncontrolled factors could be road surface conditions, crowd turnout, level of participation, etc.