For AGES, our class has been having disputes about how the average uncertainty is calculated in physics.
Here are 2 options that we are confused between
So if we want to know the Avg uncertainty and values are 44.3 ± 0.2 , 44.7 ± 0.2, 44.9 ± 0.2 and 44.1± 0.2
1) Average uncertainty = (Max value - Min value)/Total number of values
Avg uncertainty = (44.9-44.1)/4
We got this from an IB Physics uncertainties book... I can't remember how old it was but i think maybe around 2007 or more recent.
But this seems outrageous! You honestly can't just do that can you?!?!
2) We think it should be the way we do it in chem and maths and everywhere else!
Avg uncert = Total sum of uncertainties/Total number of values taken
Avg uncert = (4*0.2)/4
Avg uncert = 0.2 !
This is sooo much more logical.
And at the same time they say that you need to take the greater uncert value, which is just 2 in this case.
The problem is that method 1 gives you the same uncertainty (±0.2) in this example, but in various other problems that we have had in class it gives a greater uncertainty than ± 0.2 and it is illogical to use a greater value as the uncertainty.
How do you guys calculate Average Uncertainties?