How to evaluate the deviation of the value from the expected value?

Question

Mathematics

Hello, I have a question.
I have a series of numbers, exact values ​​( Actual distances between points on a plane).
With the help of software, I measured the distances between these points, but with the help of two different implementations.
How now to compare the results in order to understand which method is better?
Using the least squares method?
Thanks
Values ​​in the form (Random example)
Real distance between point 1 and point 2 : 34
Method 1 distance between point 1 and point 2 : 33
Method 2 distance between point 1 and point 2 : 35
Real distance between point 1 and point 3 : 54
Method 1 distance between point 1 and point 3 : 55
Method 2 distance between point 1 and point 3 : 43

Answer 1

There are such things as variance and standard deviation. If this does not tell you anything, then you should use the relative or reduced error.
For your examples, relative errors: 3%, 3%, 2%, 20%.

Answer 2

The main idea is written above. From myself I will add - for two experiments (two points in each of the samples), no results will be statistically significant. In human terms, this means that it is impossible to draw a correct conclusion from such a small data set.

Answer 3

Still probably: expected value at you is. The only question is squaring (rms value) or taking the modulus (modulo average). There is a difference, in that in the first case, a random point that is far removed has more weight. In probability theory, the first method is adopted. VAR(X)=E[(XE[X])^2] where E[X] is the expected value, and the standard deviation is sqrt(VAR(X))
(generally like "perpetual" student to perpetual student: here is the third chapter )