"Error range"? I've never heard that expression before, do different scientific disciplines have different error ranges? Who determines what that range is?
Error range or margin of error applies to every measurement ever taken. It is used to indicate the potential inaccuracy of any stated measurement.
Any legitimate poll, for example, will always have a statement that says something like 'accurate within 5% 19 times out of 20'. All of the measurements on a blueprint will have a stated tolerance for error. If the print calls for a 1.000" square block to be machined it will say 1.000" +/- .002. This means that the block can be 0.998 or it can be 1.002 inches and still be acceptable. It also means that your measuring equipment must be capable of measuring .002 of an inch.
An error range is determined by the accuracy of the equipment or method being used. It is an essential acknowledgment that measurements are seldom 100% correct and if you do not allow for potential errors then they can accumulate and lead to really big errors.
Say that we want to calculate the age of the earth and all we have is the bible for evidence. We add up all the ages of the folks mentioned there and we know from this that the earth must be at least 6000 yrs old or whatever it is. However, this tells us nothing about how much older the earth might be. Therefore, the error range for this calculation is minus 0 yrs plus an infinite amount of yrs. Immediately we can see that it is not a very useful calculation.